I'd never seen or heard Allen until a few months ago when I caught the end of a speech of his on C-Span. I missed the speech, actually, but saw him talking to the crowd afterward and he knocked my socks off. I was very impressed and thought, Oh, boy, where have you been all this time? Then saw him on Fox or MSNBC. He was one of several on a panel, supposed to give quick answers to something or other. He hardly opened his mouth and they'd cut him off. Then saw him being questioned outside a senate chamber. Same thing. He'd hardly said Boo, and they cut him off. I came to the conclusion that he needs, really needs, to take a speed talking course. However, he listens to people and treats them with courtesy and dignity. No small thing.
He does give a good speech ... and he starts with a sunny, regular-guy personality ... people tend to just like him.
The most "impressive" of the potential candidates ... as far as smooth talking, quick thinking television skills ... is Romney.
Maybe a bit too slick, though ... I think Allen might wear better in the long run.