iPad Pro for Graphic Designers

My wife is a graphic designer in DC and is always looking to improve her design game. With the latest updates from Apple on their iPad Pro matched with their Pencil, I was wondering if this would be a good tool for her to use for her job. I bought her an iPad Air 2 a couple of years ago, but I see the iPad Pro as a better tool for her, especially with the Apple Pencil.

Does anyone have experience with these and some advice? I wanted to ask before shelling out $800+ for both devices. Also, any advice on size (10.5" [which just came out yesterday] or the 12.9") would be helpful too.