Great Review ! I actually have a surface pro I bought two years before I sprung for the 22inch xp-pen artist 22E Pro https://www.xp-pen.com/product/63.html drawing display tablet, and that is a display tablet and a computer so it requires no extra hook up. But I bought it for 500 bucks which is way out of your price range. Usually stand alone systems cost quite a bit more than the ones you have to have a separate computer for.

Also, when I bought my xp-pen artist 22E Pro and started using it, I was blown away with how much better it felt to draw with than my surface pro. Not to be stuffy, but systems that are actually made solely for drawing definitely have an advantage over systems that can be used for anything. As artists we can tell. The surface pro is nice, but the lines for the pen had a bit of jitter and I could never blend the way I wanted to when I paint with it. Also the pen would sometimes have issues with running on the screen, at one point it felt like my flow was stopping every 5 mins. That last part might have been because it was getting old though...I only use my surface pro when I'm on the go now.