Texting on a number pad never looked hard to get used to, it just looked slow (and still is). They wouldn't hold speed competitions for it if it was fast.
T9 drastically improves typing speed on numpads. I could definitely type faster on my old Nokia 6310 than I can on my iPhone. I've only had my iPhone for a year but you think that'd be long enough to learn how to type on it.
It's almost like my dream phone.
One thing I've found helps a lot is to just allow yourself to finish a word with a mistake in it and hit space, assuming the auto-correct will get it right. It feels backwards at first, but I think "scrolling" or "backspacing" through text requires a lot more of your attention/a context switch than just correcting at the end of a word.
Do you know how many times either device made me sound foolish by sending "What the duck?" or "This is ducking ridiculous!" :)
And that doesn't help for words it doesn't know. Turning auto-correct off might actually be a good idea for me. I'll have to try it and see if I like it any better.
I have now had an iPhone since the first generation and I still suck at typing on one (on the 3GS now). Auto-correct seems to hurt me more than help even after earnest efforts to trust it and stop hitting backspace.
Also you can't do T9 without looking at what's selected.