It never occurred to me to ever buy an iPad Pro. If you want a productivity machine, buy a MacBook which is the best laptop money can buy. If you want a tablet (for consumption), buy an iPad Air 2 which is the best tablet money can buy.
Well even if you never use the Pencil or keyboard attachment for the iPad Pro, it will be a better tablet than the Air 2. It's faster, more powerful, has stereo speakers that can adjust to orientation, a variable rate display, etc.
The only thing I think you could argue against the Pro for is the size. It may too big to really use well as a good tablet, but that has yet to be seen, and I think it likely ultimately won't be a problem.