I quite like the S3. First things first, it has totally replaced my iPad Air. I use the S3 as a pure tablet (browsing, reading, inking). What I like about it: (1) aspect ratio; (2) lightweight; (3) fanless (and it stays cool); (4) nice screen.
However, I also think there are some areas in which it could be improved: (1) better battery-life; (2) It could be a bit more fluid (this is most likely a function of W10 rather than the S3 though I do think the device is a trifle under-powered.
One thing that I think the S3 lacks is cover. By this I mean an attachment that works just like the Type KB, but without the keys. In other words, it would be like the Touch Cover without the keyboard mechanism.
Otherwise, it is an excellent device (for my purposes - of course, YMMV).