I don’t see any of the candidates wanting Rubio as their VP simply because he would easily overshadow them (or at any rate, any of those now considered likely Presidential candidates).
At the same time, I don’t think most people would vote for a Presidential candidate simply because they liked his VP. McCain tried that with Palin, and while it definitely helped his numbers, there’s no way it would ever be enough to make up the winning number for a loser Presidential candidate.
If Sarah Palin wasn't the VP on mcpain's ticket, he'd have carried Arizona.
The VP does indeed make a difference, look at JFK and LBJ, even with all the cheating in Chicago and West Virginia, no way Texas or any southern state goes to JFK without johnson as his VP.