Why do you find MIchael Steele unimpressive? I live in the People’s Republic of Maryland where we have had a lot of exposure to him, and I find him impressive as anything.
He may well be the most impressive guy in Maryland, I don't know. But I don't see him having a coherent conservative worldview. One red flag, ironically, was his early support for McCain in the primaries.
Take abortion, for example. While he claims to oppose abortion at all stages, he has also expressed support for Roe v. Wade, although he then became elusive and wouldn't elaborate despite continued questioning.
I don't think he's a bad guy, but I'm not convinced he's as bright as people think he is. That's mostly a gut reaction to his frequent TV appearances on Fox News - I'm just not that impressed.
McCain could do worse than Steele, but I think he could also do a lot better.