Stopped by a local MS store, played around with one for about 20 minutes, here are my impressions:
How it feels: This thing screams premium when you handle it. Completely solid and secure in the hand. Very light. I own a Nexus 7, and the SP3 almost feels like it's lighter than the N7. The bigger surface area of the SP3 gives you the expectation that it should weigh a lot, but its actual weight turns that expectation up-side-down and gives the illusion that it's lighter than it really is (vs the expectation). My old iPad 1 feels heavier than a SP3.
Lapability: Without a type cover, it works like a dream with the vari-angle kick-stand. In fact, I'm not sure that I need a type cover whenever I'm using it on my lap. The on-screen keyboard works just fine. With the type cover (using the extra raised position), I had no problems getting it to stay balanced on my lap, even when I'm crossed over and it's on one lap. I could type just fine on a lap. Overall, I give it 90% of a normal ultrabook's lapability.
Pen: This is the only slightly disappointing aspect I found. Writing with the pen doesn't quite match the precision of writing on paper. There is still a perceptible delay in the ink trail vs my motions, although it is superior to every other device I've ever tried. When scribing sentences like I would on a pad of paper, using my normal writing speed, I find that the results are about 80% the readability I would have on paper. If I was going to use this for serious note-taking, I'll need to adjust (lower) my writing speed.
Overall, this is a very drool-worthy piece of tech. I'm still holding out for a Broadwell refresh, but once that happens (hopefully 6 months from now), it'll be impossible to resist getting one.
