Like Clinton on the other side, Romney reeks of competence. His campaign is well run, and throughout his career, he has a history of getting stuff done. After this Bush administration, these are powerful qualities. I also respect the hell out of his accomplishments at Bain. At the end of the day however, I don't think Americans will entrust the Presidency to somebody from a non-mainstream religion. More of an issue for me personally is the radical flopping on social conservative issues, in a clear attempt to make himself more electable. This makes him a bit less trustworthy in my eyes than say, a McCain, who like him or hate him, you know where he stands.
I do think that Romney would make a fine President though.