I'd say that the keyboard is not the hindering factor; it's the smaller screen that may not be as nice if you are coming from the 8700. They keyboard and SureType are both perfectly effective. I remember reading reviews about the Pearl that complained that the keys are so small. Really, the keys are not that small. They are very close together though. Still, the keys are large enough that I never have a problem with hitting an adjacent key.
If you don't mind the smaller screen, the Pearl's size far outweighs any inconvenience from learning the keyboard.