The SP2 Wacom setup was not perfect by any stretch of the imagination, in my experience -- accuracy was terrible in the corners / near the edges, and parallax was a serious issue, if you did not write/draw with the pen perpendicular to the surface of the screen, there was a significant offset from the tip of the pen to where the line was actually drawn. These were bad enough to turn me (and at least one professional artist that I know) off from buying one.

The move to N-Trig hypothetically fixes both of these. Early reviews/videos say that corner accuracy is greatly improved, and the lack of a separate digitizer layer allows a thinner optical stack, reducing parallax (and allowing the device overall to be thinner).

Driver support has historically been an issue, but msft seems to be improving things significantly.

There are fewer levels of sensitivity and hovering doesn't work quite as well, but I am overall reasonably optimistic about the switch.