Running QBs do better in the college game and pocket passers are better in the NFL. I do think mobility is important. Andrew Luck has the right mix if you ask me and I have always admired the elusiveness of Big Ben. The problem with Vick and to a lesser extent RGIII, is that running is such a huge part of their game and they are not big men. They are not built to take hit after hit from running. Tim Tebow is a terrible passer and relies solely on his ability to run around and throw the ball (inaccurately). However, he seldom is hurt because of his size.