One tip on getting used to SureType is to NOT look at the words as you are typing.
This is because when you see the word initially being typed incorrectly there is a tendency to want to stop and correct the word with multi-tap.
RIM suggests NOT looking at the words as they show up on the screen for precisely this reason [SureType has not yet guessed the correct word you are typing].
I experienced SureType on my 7100t and when I first got it I did look at the words and stopped to backspace so to correct them. Once I stopped doing that, I loved SureType.
There is a learning curve with SureType as you manually have to teach it unique words. I am a lawyer in federal court. I had to teach my 7100t all sorts of legal words and names of places and people.
Once SureType learned terms unique to my business/profession, it was smooth sailing.
Don't turn off SureType, give it a chance for a month or so. You will get used to not looking at the screen and letting SureType do its thing. Come back in a month. You will report that SureType is the greatest feature on the 8100.