I've used them all and THE fastest and most accurate entry on mobile by far was the psuedo-t9 keyboard on the Blackberry 7130. It was so good that it was frustrating to use the full keyboard on later Blackberry models.
I wonder how many people actually experienced this keyboard in the world, perhaps only in the thousands?*
Seems they had a name for it, SureType:
https://en.wikipedia.org/wiki/List_of_BlackBerry_products#Fi...
edit: ah I see it was used on other more popular models, too. Blackberry Pearl users should chime in!