I've been testing Microsoft's new Surface Go, the smaller and more affordable version of the Surface Pro laptop/tablet hybrid for several days. The Surface Go starts at $399, but the model Microsoft sent me starts at $550 before you add a keyboard, pen or mouse. It's a decent laptop, but not a very good tablet. And it's way too expensive for what you get. Here's what you need to know.

What's good

The Surface Go is a good laptop but not a great tablet. CNBC | Todd Haselton

I'm a little bummed. Going into this review, I was almost certain that I was going to end up replacing my iPad Pro 10.5 with a Surface Go. There's a lot to like about the device on paper. It runs a full version of Windows 10 but ships with Windows 10 S, a lightweight version that can only use apps from the Windows app store. Luckily, you can upgrade to the full version of Windows 10 for free and use any app you want after that. I'm a big fan of Windows 10, especially because I can run all of the apps required for work. I've been using the Surface Go exclusively for work since it arrived at my desk. I love the 10-inch size of the Surface Go. It's really light, weighing in at just over a pound even with the keyboard attached. I could barely tell it was in my backpack, which is a huge improvement over my work-issued Dell laptop that weighs several pounds. The touchscreen is sharp and bright, a vast improvement over what you'd get from similarly sized netbooks back in the day.

The kickstand can adjust to all sorts of angles. CNBC | Todd Haselton

The keyboard accessory, which will run you another $130, is compact, but not too small. I was able to get adjusted pretty quickly, but the keys sometimes felt a little too plasticky and sticky. It also has a large and accurate trackpad. I was able to do everything I needed for work pretty well. I often have more than 10 tabs open in Chrome and music playing on Spotify. Any modern laptop or tablet should be able to handle that, and the Surface Go did fine. But it did get sluggish as I started to run more apps. I liked it when I connected it to a Microsoft dock with HDMI and USB ports so I could use a larger screen and a full-size keyboard. It did a good job with all of that.

I liked hooking it up to a dock. Here, it's streaming CNBC to a TV and letting me surf the web. CNBC | Todd Haselton

I don't usually draw on the screen, but the Surface Go worked just as well with the Surface Pen as the Surface Pro does during my occasional use. I also like the design. I popped the keyboard off and caught up with TV shows at night while the Surface Go stood balanced on its pop-out kickstand, which feels sturdy and bends almost all the way back so the tablet is practically flush with the table. The kickstand wasn't ideal when I tried to use the Surface Go in my lap, but the whole thing is so small that it's still easy enough to balance. The speakers are good for such a small device and seemed to be on a par with my iPad Pro 10.5.

The Surface Go can recognize your face and automatically unlock. CNBC | Todd Haselton

The Surface Go also has Windows Hello, Microsoft's facial recognition feature that's used to unlock the device. I found it to be accurate, and it reliably unlocked my Surface every time I sat down. Apple is expected to add a similar feature to its new iPads this year.

The keyboard is tiny but I got used to it. CNBC | Todd Haselton

The model I tested ships with 128GB of storage, which should be enough for many. The base model only has 64GB, but there's also a microSD card slot on the bottom of the Surface Go that you can use to expand the storage without spending too much money.

What's bad

The Surface Go isn't good as a standalone tablet. CNBC | Todd Haselton

The Surface Go is a good laptop but a bad tablet. That's a problem, since the keyboard isn't included to give you that full laptop experience out of the box. Windows 10's tablet interface still stinks, and there aren't a lot of popular apps that were built for Windows 10 in tablet mode. The iPad still has the best library of tablet apps. I like using tablets for reading, but Amazon's Kindle app clearly wasn't built for the Surface Go, and Microsoft's bookstore lacks a lot of titles, including some on The New York Times' best-seller list. The Times, The Washington Post and other popular publications are also missing. While I could check any website, scrolling was sometimes too jittery and annoying, especially while holding the tablet with one hand in bed at night.

It's nice a compact like a notebook. CNBC | Todd Haselton

Also, while Apple and other companies have worked to remove bezels — those large borders around the edge of the screen — from their gadgets, Microsoft didn't do that with the Surface Go. The Surface Go's bezels are so wide they're almost comical. While it doesn't hinder performance, it makes the tablet look dated from the get-go. Finally, battery life is pretty bad. Microsoft advertises nine or more hours of use, but I never got close to that. I usually saw about four or five hours of use with Chrome and Spotify open. I could save battery life by using Microsoft's Edge browser — Windows 10 said Chrome was draining the battery a lot — but I prefer Chrome.

There's one USB-C port, a headphone jack and a charging port. CNBC | Todd Haselton

As far as ports go, there's just a single USB-C plug and standard headphone jack. (USB-C is the new USB standard that's starting to replace the USB you're used to.) Unfortunately, a lot of accessories still don't work with USB-C, so you might need to buy an adapter that adds more ports.

Should you buy it?

I like the Surface Go a lot as a very portable work computer, but it's not the right solution for most people. It's too expensive for what you get. That stinks, because I had every intention of buying one before I tested it. The Surface Go starts at $399. That model includes 64GB of storage and 4GB of RAM, but most people need more RAM than that for a good experience. You should at least buy the model I tested, which costs $549 and has 128GB of storage and 8GB of RAM. Keep in mind this is only for the tablet. The keyboard will cost you another $100. (The keyboard model I tested has a nicer finish and costs $130.) Before you even add the Surface Pen (another $100) you're already at $650. I wish Microsoft sold the model I tested with a keyboard for $400. That sort of price would change my mind.

It gets really compact and is great for carrying around. CNBC | Todd Haselton