The new 9.7 inch iPad Pro has some additional features in terms of a better camera and a screen that adjusts ambient light but none of that is really a reason to choose one over the other for most people. To me, the big question is whether you want it really big or just kind of big. I can understand why some people hate the big iPad because of the unwieldy screen size but I’m just so damn productive with it.
I agree with David; the 12.9-inch size is what finally unlocked something for me when it comes to working on iOS. Coupled with the bigger on-screen keyboard, I simply don’t want to go back to the 9.7-inch size.