MarketWatch wanted to find out what you actually get when you ask for investing tips from a so-called robo adviser.

We rounded up recommendations from four prominent robo advisers and four human ones for a hypothetical 35-year-old investor.

Read on for a detailed look at each of the suggested portfolios and how they differed. They might all be more similar than you expected.

You can also take our quiz to see if you can tell whether a portfolio comes from a robo adviser or a mere mortal.

A note about our fictional, but perhaps typical, 35-year-old: Our investor is basically average in terms of tolerance for risk, financial knowledge and money saved. This individual is investing for retirement and has $40,000 for that purpose. (Fidelity suggests that is about average for this age, and EBRI’s figures are near that level as well.) Maybe the money was in a 401(k) from an old job, and it is now getting rolled over into an IRA.

The 35-year-old has an annual income of $46,000, since that is about average for his or her age group, according to the Labor Department, as well as $4,000 in a savings account — roughly typical as well, according to the Fed. One rule of thumb is that by age 35 you should have an amount saved for retirement that is equal to your annual pay, so our test case is somewhat behind and possibly part of a nationwide retirement crisis, but that is another story.

See: Chuck Jaffe on the battle between human advisers and their ‘robo’ rivals

And: Philip Van Doorn on how a robot really can offer sound advice

Unique in liking gold: Charles Schwab Corp.’s SCHW, +0.61% robot is alone among the eight advisers in telling our 35-year-old to plunk money into a gold ETF IAU, +0.16% . That runs counter to the common advice that individuals shouldn’t invest in the yellow metal.

Cash heavy: Schwab Intelligent Portfolios also distinguishes itself by recommending our investor put 8.5% in cash. This cash-heavy approach has drawn criticism, since it can result in lower returns. Schwab defended the approach last month in an interview, and it gave a detailed defense in a blog post in early April.

Fees: One big plus is that Schwab’s robo adviser doesn’t charge a management fee.

But the San Francisco–based financial giant can make money on the cash holding it recommends, just as any bank profits from the difference between the interest rate that it pays to customers and the rate it can earn on money it told. Since Schwab is an ETF provider, unlike the other advisers, it also gets revenue through the fees tied to this portfolio’s Schwab ETFs. What’s more, the Schwab “fundamental” ETFs are smart-beta funds, meaning they have higher fees than plain-vanilla ETFs and aim to beat the market.

Keeping it simple: Wealthfront offers the simplest recommendation among the four robo advisers. It gets the job done with just seven ETFs, while the other three robots use 10 to nearly 20 different investments. But nonetheless, Wealthfront’s recommendation — 36% in U.S. stocks, 33% in international equities, 17% in bonds and 14% in real-estate investment trusts — is similar to rival FutureAdvisor’s suggestion to put 33.5% in U.S. stocks, 37.8% in overseas stocks, 16% in fixed income and 12.6% in REITs..

A $2 billion force: Wealthfront and competitor Betterment are the two biggest independent robo advisers, each attracting roughly $2 billion in investor money, according to data from an SEC tool for tracking investment advisers. A Goldman Sachs report dated April 10 said the nascent industry has the potential to attract about $400 billion eventually, but even that would represent a fraction of the $12 trillion that U.S. retail investors now have in play.

Fees: Investors don’t pay a management fee for their first $10,000 at Palo Alto, Calif.–based Wealthfront, and above that amount the fee on assets is 0.25%.

Wanderlust: Betterment has a real hankering for foreign shores, as its recommended portfolio puts 48% into non-U.S. stocks. That is above what’s suggested by the other robo advisers, the four humans and one possible benchmark, the American Association of Individual Investors’ moderate portfolio. (More on AAII’s take later.) But experts who warn American investors about home-country bias might prefer Betterment’s plan.

Vanguard-lust: Betterment isn’t so unique in its reliance on Vanguard, the index-investing pioneer. Betterment and two of the other robo advisers picked mostly Vanguard exchange-traded funds, and the four human advisers all recommended only Vanguard products. Schwab, with its own ETFs, was alone in using only a few Vanguard funds. “You can see why Vanguard is growing so much,” said Michael Kitces, Pinnacle Advisory Group’s research director.

Also read: Morningstar researcher sees ‘dark side of Vanguard’s success’

Fees: Investors pay a management fee of 0.3% for their first $10,000 with New York City–based Betterment, or $3 a month if they’re not auto-depositing at least $100 a month. The next $90,000 costs you 0.25%, and beyond that the fee is 0.15%.

Smaller, different: With $520 million in investor money, FutureAdvisor isn’t as big as Wealthfront, Betterment or Schwab. But the San Francisco–based robo isn’t timid, with spokesman Chris Nicholson stressing it can differentiate itself from rivals by sending its algorithms out to a customer’s multiple existing accounts, rather than making the user move money to a new account.

Robots like more funds: The portfolio recommended to MarketWatch would have 12 ETFs instead of the 10 shown, Nicholson said, if the 35-year-old had $100,000 rather $40,000. “Normally we recommend that investors diversify across 12 different funds,” he said in an email. The four robo advisers generally used more funds than the four humans, recommending 11 on average versus six on average by the nonrobots. Pinnacle’s Kitces said a higher number of funds allows a robot to do tax-loss harvesting and tilt portfolios toward value, dividends or other factors that are “reasonable.”

Fees: Investors pay a management fee of 0.5% to FutureAdvisor, or users can get free recommendations, then make the suggested trades on their own.

Targeting Gen X and millennials: Pamela J. Horack said that while she targets young professionals and working families, many advisers won’t work with a client with $40,000 or less to invest. “If people outgrow me, then that means I’ve done my job,” said Horack, a certified financial planner in the Charlotte, N.C., area whose Pathfinder Planning is part of the XY Planning Network, a group of fee-only advisers that was co-founded by Pinnacle’s Kitces and focuses on Generation X and millennials, also called Gen Y.

Just four ETFs: Horack’s portfolio uses the same four funds that appear in the Vanguard 2045 target-date fund VTIVX, -0.70% , except it goes with ETF versions. She doesn’t put as much into stocks as the 2045 fund, and she dials back further by keeping 2% in cash. MarketWatch made it clear to each human adviser that it was asking for a recommended portfolio for an article.

Fees: Horack said she would work on a project basis with this 35-year-old, rather than charging a percentage fee on assets. This client probably would be directed to pay $1,800 for a comprehensive financial plan, she told MarketWatch. That includes a recommended portfolio, retirement plan and insurance review plus budgeting help. (Pinnacle’s Kitces emphasizes that human advisers in general will do more than just manage a portfolio, as they also can offer guidance on home loans, college savings and many other money matters.) Horack said she doesn’t do investment management, so the client would implement the recommended portfolio.

Also see: Chuck Jaffe on the battle between human advisers and their ‘robo’ rivals

The human touch: Jared Kizer, Buckingham Asset Management’s chief investment officer, described his recommended portfolio as “not overly complicated” and stressed that he would go over potential behavioral pitfalls with the client, such as avoiding the tendency to bail out at the worst possible times. He said his firm is “generally not that concerned” about competition from robo advisers, because much of a human adviser’s value comes from personal interactions and helping clients respond to events. “There’s not as much overlap as people think,” Kizer told MarketWatch.

Fees: A 35-year-old with $40,000 might end up working with St. Louis–based Buckingham Asset Management through a wealthier family member who is an existing client. Or he or she might go for Buckingham’s “Asset Management Offering,” which charges either a minimum annual fee of $1,200 or 1.25% of assets.

Not as stock-heavy: Everette Orr said the 35-year-old might want to go with a Vanguard target-date fund, but such funds are aggressive in how much they put into stocks. “If they’re really middle-of-the-road, then I would probably back them off,” said Orr, who runs McLean, Va.–based Orr Financial Planning. He would instead recommend the Vanguard STAR Fund VGSTX, -0.40% , a fund of funds that is roughly 60% stocks and 40% bonds.

A significant difference: Orr’s recommendation puts less into stocks than the other three human advisers’ suggestions. And among the robo advisers, they’re all more equity-heavy, except for Schwab, which also only sticks about 60% into stocks. Kitces said that while the eight recommended portfolios are “not massively different,” the variations in how much gets put into stocks is “actually pretty material.”

Fees: Orr said the 35-year-old would likely pay a $600 fee, as he charges $200 per hour and that would cover a two-hour, face-to-face consultation and one hour of prep work. He added that he’s not currently taking new hourly clients, and for clients with at least $300,000, he charges 1% for the first $500,000, then 0.5% for the next half million and 0.25% beyond the $1 million mark.

Just going with a target-date fund: The Vanguard Target Retirement 2045 Fund VTIVX, -0.70% is a “reasonable place to start,” and the 35-year-old should know it is a long-term holding that “could really fluctuate,” said Catherine Hawley, a Monterey, Calif.–based adviser who is part of the Garrett Planning Network. Going with a Vanguard target-date fund isn’t that imaginative, but finance-industry commentators like Felix Salmon have argued that it has been a “gold standard.”

Not competing, but complementing? Hawley said robo advisers “can be a complement” to what she provides, and she has a client who has used Betterment for allocation recommendations. “I kind of view the portfolio as one part of the plan,” she said, adding that she also focuses on aggressively saving for retirement, avoiding credit-card debt, securing insurance coverage and other issues.

Fees: Hawley said she charges $220 per hour, so a client could expect to pay at least $440 for an initial appointment, and he or she might end up spending a total of $1,500 for the year due to follow-up meetings to address other money matters.

A possible benchmark: If all these varying portfolios have left you wanting standard advice of some sort, this might help. The American Association of Individual Investors has published asset-allocation models, including one for a moderate investor who is 35 or older. And that is shown in the adjacent graphic.

Look here for AAII’s recommendations for aggressive or younger investors, as well as its suggestions for conservative or older investors.

Read more: Philip Van Doorn on how a robot really can offer sound advice