It amazes me that Aikman was the last QB drafted number 1 overall to win the superbowl. I know Elway was a first, but I'm talking most recently drafted.
I think you'd have to be absolutely crazy to draft a QB in the top 5. If I were a GM I would never draft a QB until about 7-10 range...investment isn't as high, and pressure isn't as heavy on him to come in right away and succeed.
There are only two positions I'd draft in the top 5...
RB and LBer.
I wouldn't touch any other position in the top 5, not just this draft, but any draft.