I think the best keyboard for the iPad Pro 9.7 is Apple's very own Smart Keyboard. I have been using it for 3 weeks now and I have gotten used to it. Tactile feedback from the keys are good and comfortably soft. Initially I wasn't very happy with it because the keyboard is of a netbook size and adjusting to this size gave me a lot of problems. But now that I have accustomed to it, it's very nice to type with and I can now finally touch type on it at blazing fast speeds. The fabric material of the keyboard gives me a very warm touch as I type, very comfortable to rest my fingers on as compared to the other keyboards which have plastic keys which is cool to the touch.
It's the only keyboard that does not need to run on battery and thus no need for charging and no need to turn on/off and it's the only one that connects to the smart connector of the iPad Pro. This feature is really a winner IMHO. I have previously used Bluetooth keyboards with my iPad Air 2 and it was always a hassle to on/off the keyboard before and after I use the keyboard. Battery runs out halfway thru typing and had to switch to on-screen keyboard. Overall, I hated using Bluetooth keyboards but didn't have any other alterternatives so Apple's Smart Keyboard is a godsend to me.
It's attached to the iPad Pro all the time. I really like this feature because it is always there when I need it, if I don't need it I just fold it over and it's out of sight. Also, it is very slim so the bulk of the keyboard is not very noticeable to me.
This ONLY complain I have about this keyboard and I really do mean ONLY complain is the missing sleeve to house my Apple Pencil. I wished there was a place for me to slot my pencil somewhere on the keyboard cover so that it is always there when I need it. I believe that the iPad Pro, Smart Keyboard and Pencil inseparable and they need to be attached to each other one way or another.
This is just my personal opinion about this keyboard and I am sure some of you guys will disagree with me, that is fine as to each it's own. For those who is on the fence on which keyboard to get, I hope you read my post with an open mind and good luck in deciding the best keyboard for your new iPad Pro.