I have one of these under a different brand name. They work, and they are handy, but with a couple of caveats.
It sucks batteries, and continues to drain the batteries when it is turned off. Either take the batteries out or get rechargeables. These would be SO much better with a built-in rechargeable battery.
Color scans tend to be a little overexposed (if that’s the word I’m looking for…same effect). Black and white tends to be fine.
You need to have really steady hands to get a straight scan. It does a pretty good job of compensating for slight variations in direction as you scan, but only slight ones.
You can have fun with these things by rolling them over (and they do use rollers to determine how much the scanner has moved) things, like people’s faces and such.