I've made no secret over the years about the fact that I'm not particularly good at typing on glass. Part of the reason is ham-hands and my preference for dictation. Those, however, are just excusees. The real reason is that after a lifetime of touch typing, I've never felt particularly good at typing on glass. It felt like productivity molasses.
A few things, however, have swayed me. It started with the iPad Air. On that machine I got quite good at thumb typing in portrait mode. It's nothing like touch typing but still pretty great to sit on an airplane and thumb my way through an outline or a pile of email.
Speaking of airplanes, I recently took a flight where I was seated right between the window and a big guy that made pulling down the tray and using my iPad Pro's Smart Keyboard cover impossible. I had four hours on that plane and was determined not to thrown in the towel. So I placed the iPad on my lap and started typing. I then went into one of those hypnotic work-states that I often feel on airplanes and before I knew it the pilot announced we were about to land.
I got a lot of work done typing on glass that day and it really opened my eyes. There's a lot to like about typing on the 12.9" iPad glass. You can switch keyboards easily. If you're paying attention, the recommended word selections are pretty good and can speed things up. That eye-opening flight was a month ago and now I find myself typing on glass a lot more than I've ever done before. This post was typed on glass (more out of convenience than to prove a point). When you get right down to it I really don't think there is much a speed loss typing on glass with the big iPad Pro.
Jason Snell's brought math to this party. He recently ran his own typing tests where he found he only had a 17% loss in speed typing on the 12.9" iPad pro glass over a keyboard. While I don't think it is quite that close for me, I don't think Jason is far off. Moreover, if I spent a little bit more time getting better at this glass keyboard, I'm certain I could close the gap further.
All of that said, there are still definite pain points. Text selection is still far easier for me using a keyboard. Also, typing on glass at least once a day my finger accidentally hits the keyboard switch button which brings my work to a screeching halt. On that note if I were in charge, I'd make the keyboard selection button something where you had to press and hold to switch between keyboards.
I'm not ready to give up my Apple Smart Keyboard cover anytime soon but I can tell you I'm much more receptive to typing on glass now than I've ever been before.