Having had him several times as a guest on my show in Rochester, I can tell you David Paterson is a sharp, articulate, witty guy, comes across very strongly on the air in a live situation. He was an excellent guest.
Of course, being a host, relating to guests and callers and and bringing the best out of them, is a whole different proposition. We all know great guests who couldn't make it happen as hosts (remember David Lee Roth? Mario Cuomo?).
Paterson may be different because he's getting the experience carrying a show as a guest host that many of the other strong guests who tried to make the jump to host never got. He's working into it gradually and that will serve him well.