The experience comparison:
Conservatives like to say that Palin has had more "executive experience" than Obama, or Biden, or even McCain. But that's not much of a metric. The president of the local chess club, by virtue of being in an executive position, outranks Senators on that score.
The relevant question, at a minimum
Who, among the nominees, have been part of the national discussion during Bush's second term?
The Senators. Also Romney. And Ron Paul. All sorts of folks.
Palin, not so much.