Hosting a first-time visitor to San Francisco sure throws into stark relief the best and worst of our beloved, yet frustrating, city. Your heart can swell with pride and beat a bit faster with embarrassment in only minutes.

We were lucky to have my husband’s brother and his new wife visit from England for two weeks recently. My brother-in-law has visited numerous times, but it was my sister-in-law’s first time in California and first time seeing the Pacific Ocean.

It was a time to rediscover classic parts of the city we take for granted, those institutions we adore but easily ignore as the years slip by. Riding the cable cars, a nightcap at Top of the Mark, taking photos of the Painted Ladies, an Italian dinner in North Beach, seeing “Beach Blanket Babylon.”

All worthwhile, by the way. Especially the latter, with its new Sarah Huckabee Sanders character. Picture a woman with a permanent scowl crooning remade lyrics to the tune of “Can’t Take My Eyes Off You”:

“I’m just too good to be true/ I’ve got some fake news for you/ God says I’m heaven to touch/ The rest of you, not so much/ For I was sent here to say/ The same ol’ crap every day/ To all the Muslims and Jews/ We got our eyes all on you.”

Then there’s sharing your regular fun city routine: eating dumplings, sushi and Mitchell’s ice cream. Driving across the Golden Gate Bridge. Visiting pumpkin patches and hanging out on the beach in Half Moon Bay. Catching the latest show, “Aladdin,” at the Orpheum.

But as quickly as that joyful I-can’t-believe-I-live-here feeling comes, it can go. We took our visitors — big barbecue fans — to the new Hazel Southern Bar & Kitchen in Mid-Market. The dinner was enjoyable, and the collard greens were especially delicious.

But Mid-Market at night? It’s sketchy during the day, but downright distressing after dark. Row after row of injection-drug users shooting up in plain view, their spoons and needles spread all around them. Same with the Civic Center BART Station. Not too pleasant during the day, pockets of it a shooting gallery at night.

It’s like “Night of the Living Dead” come to life — right in the middle of San Francisco — and it just seems to be accepted by city leaders and law enforcement as part of life here. Incredibly, the Department of Public Works’ hot-spot crews, which mostly clean homeless tent camps, collected a jaw-dropping 15,046 dirty needles in October alone — an average of 485 per day. They collected 17,580 needles the month before.

My sister-in-law, Rachel, said she’d only seen heroin use in movies before, never in real life. And she’s pretty sure that if somebody were that blatant about it in London, police would intervene.

(Yes, that’s one price to pay for staying in my home — the reporter’s notebook and pointed questions can be whipped out at any time.)

My brother-in-law, Paul, hadn’t visited in three years and said homelessness was much worse this time. They ventured to Frena, a kosher bakery, on Sixth Street and were saddened to see homeless parents and kids wandering the downtrodden area just a couple of blocks from where Ashton Kutcher was addressing the deep-pocketed Dreamforce crowd.

“The class divide is so, so easily seen here compared to home,” Rachel said. “There is just such a big divide between people who have so much and people who have so little.”

The 31-year-old operations manager isn’t naive. She lives just outside London and has traveled the world, including all over Europe and parts of Asia. She said she’d never seen so much homelessness or mental illness before coming to San Francisco.

“If it didn’t affect you, then you wouldn’t be human,” she said. “You could become more immune to it if you see it every day, but you shouldn’t.”

These mixed reports jibe with the findings of a visitor survey commissioned by S.F. Travel. The agency, which promotes San Francisco to tourists and business groups, hired a market research company to ask questions of visitors at major tourist sites, transit hubs and hotels between January and June.

The survey found that a third of respondents were on their first trip to San Francisco. Two-thirds of them came from other states and one-third from other countries.

Asked what they liked best about San Francisco, respondents cited the weather as No. 1, followed by the food and scenic beauty. Asked what they liked least, they cited traffic, homelessness, the expense, the dirty streets and the smell. Eau de San Francisco? Not likely to be bottled for sale anytime soon.

Despite the gripes, 96 percent of respondents said they’d return to San Francisco, which is a good thing for locals, seeing as how the tourism industry supports 80,000 jobs and brings $9 billion to the city each year. (That includes $725 million in local taxes going straight to City Hall, a sizable chunk of the city’s $10 billion annual budget.) More than 25 million people visited San Francisco last year, an increase of 6.5 million since 2008.

“People are in awe of the magic of San Francisco — all the things we love: the rolling hills, the fog, the trolley cars, finding those hidden neighborhood gems,” said Cassandra Costello, vice president for public policy at S.F. Travel.

That was true among the tourists waiting at the cable car turnaround on Monday morning. Phil Barlow, a 41-year-old visitor from Manchester, England, said his best experience so far was attending a 49ers game on Sunday, not something most San Franciscans are raving about these days.

“They won!” he said, also a rare utterance.

But his least favorite part was seeing so much homelessness and drug use.

“It’s kind of scary — a bit off-putting,” he said. “But I suppose what can you do? That’s something for the politicians to worry about.”

Yeah, you’d think.

Down the line from him, Bob Brockman, a 67-year-old visitor from Wyoming, was wearing a brown leather jacket to match his brown leather boots. It was his first visit to San Francisco, and he said the people-watching was top-notch. So was the seafood at Waterbar.

“We just got here, but we’re having a hoot!” he said.

He said he was surprised by the number of homeless people, noting “half of them are truly homeless and half of them are con artists.” Regardless of which half is asking, he gives them change.

“I’m lucky, and I’ve got a little bit extra,” he explained.

Everybody I asked said San Francisco has its flaws, but they’d come back. Thankfully, my sister-in-law said so, too.

Have you hosted visitors recently? What did they think of San Francisco? What are your tips for tourists? Responses may be included in a future column.

San Francisco Chronicle columnist Heather Knight appears Sundays and Tuesdays. Email: hknight@sfchronicle.com Twitter: @hknightsf