I'd argue that the #1 or #2 key addition that "Pro" gets you (the Pencil being the other #1 or #2) is the "Smart Connector" for the integrated keyboard (http://www.apple.com/smart-keyboard/).

The ability to add the keyboard and the pencil illustrates the distinction Apple is trying to make between the Pro and the vanilla 9.7 -- creation vs. consumption.

After all these years, they are still persistently trying to position the iPad as a creation tool. Maybe it will work.

The list of things I absolutely can't do on an iPad is fairly small these days. (This is distinct from things that I would prefer to do on a Mac/PC, but there are things that I would prefer to do on the iPad, too.) I think Apple may need to do a better job of showing, well, more utilitarian tasks that can be done pretty easily on the iPad.

Having said that, I do wonder if one of the unspoken stumbling blocks is that even if an iPad is a great portable computer in many respects, it's only a portable computer. A lot of people "dock" their laptops to get work done. (Or to write comments on Hacker News when they should be getting work done.) I love traveling with my 9.7" iPad Pro and keyboard, but even if future releases of iOS address all the nitpicks I have with it, there are times I want to be sitting at a desk in front of a big monitor. I don't see that coming to iOS any time soon.