Each person's situation is different. I had an iPad Air. The new iPad Pro 9.7" is twice as fast, better screen, new hardware features, such as a much better camera, and attached/detachable Smart Keyboard and Pencil stylus option. It's a huge upgrade from the first generation Air for me. However, it's only moderately faster than the iPad Air 2 with the same 2GB of RAM for running programs and keeping data available instantly for recall. That, along with a base $100 price increase makes that upgrade option more problematic.
Logically, that makes buying the new iPad Pro 9.7" a very iffy option for anyone with the last generation Air 2, unless the new features are important for you. However, for anyone with an older iPad, or none, the new iPad Pro 9.7" is the new world class standard for those in the market for an iPad. It was a no brainier for me.