I've only spent half a day with it, but my first impressions are thus. It's partly about Android, since this is my first Android device, and partly about the Nexus itself.
It's small! It's comfortable to hold in one hand, and the keyboard is a great size — where touchscreen phones are too small for proper two-thumbed typing, and where it can sometimes (with my tiny hands at least) be occasionally difficult to reach the middle of the keyboard on iPad, I've found the keyboard on the Nexus to be a great size. Swype adds some icing to the already-nice cake.
Build quality is excellent; it has a satisfying heft without being heavy, the leathery-plastic back is nice and grippy, and it just generally feels solid and well-constructed — in absolute terms, not just for its price point.
The screen is lovely; side-by-side with a retina iPad it's perhaps slightly inferior but as general usage goes it's an absolute pleasure. When you consider the cost, it's absolutely phenomenal.