I have a BlackBerry, albeit an ancient one—8830 World Edition—and I actually turned it on the other day. Typing on it really was weird—it felt like it required a lot of physical effort to use. (And I remember thinking that BlackBerries had excellent keyboards, as opposed to the Treo; I had one of those, too, and it felt like typing on pencil erasers.)
I'm not trying to sound condescending, but a physical keyboard on a phone feels sort of like training wheels to me; something that an old-school phone person might assume is more usable than the tiny buttons of an onscreen keyboard. But then you realize how accurate the key-sensing on screen keyboards actually is, and how much less energy it takes to tap than press.
I have no idea, but I do know that when I used my old BlackBerry the other day, it felt uncomfortably like using a mechanical typewriter. I'll be curious to see how this goes.
For some reason I never get along with screen keyboards, even after 8 years or so. I press the wrong key every 5 characters or so, and the auto correct is very seldom right.
I've tried many keyboards, currently I've settled on google keyboard app. I'm very unhappy with its accuracy, but it's slightly better than the alternatives.
I should add I'm not a native English speaker, most of my phone interaction is in my native language, but when I do write English google's keyboard app's autocorrect seems to be much more intelligent. Still, the need to constantly look at it is tiring.
Maybe it's because I'm a relatively fast typist since an early age, and used to the feel of physical keys and placing my fingers just so, so I'm more annoyed with the inaccuracy of phone keyboards compared to other people, I don't know. I also tend to be very verbose in writing, compared to other people I know.
So even after 9 years I haven't touched it, I find myself still missing my old Nokia phone every time I try to write a detailed message on my new Android phone...
