My major qualms about Sen. Allen is his "less than quick" comebacks when he is either questioned in an interview, or id debating on TV...
People have made fun of President Bush all of these years...but even Bush thinks quicker on his feet than Allen seems to.
My first real internal "alert" was last year when he was asked whether President Bush should meet with Cindy Sheehan when she was in Crawford protesting...and Allen said he should...
I remember a lot of we Allen fans were a little disappointed..but really, no big deal....but, I think it has made me more leery about him...but, like you pointed out, he does have the executive experience of being a Governor..which I think is much better on a POTUS resume, than being a Senator.