The hit boxes on phone screen keyboards change size as you type. Making the keys you're more likely to hit next bigger than those you're less likely to hit next. That coupled with autocorrect can allow one to type pretty well without looking, but if you're typing made up words or words it doesn't like then you could have some trouble. There is plenty of times when I try to click one button but it's clicking the one next to it instead.Phone is hard because of the lack of physical feedback and touch locating. I do ok in a pinch but it's a pain. Keyboard absolutely. I still remember the stupid orange plastic covers we had in school to force us to learn to touch type rather than looking at the keys.
This is what I miss most about my BlackBerryPhone is hard because of the lack of physical feedback and touch locating.