If I have the number one pick I am taking Luck. Nothing against RG3, but Luck has all the tools, and has shown them the last couple seasons. I dont want to say RG3 came out of nowhere, but lets just say no one was touting him as a first round, let alone top 5 or number 1, pick before this season.
RG3 needs to show me he can play in a pro style offense. I think he can, but it may take a season or two to be at Luck's level. And by then, Luck should have progressed as well.
RG3 does have the higher upside in my opinion, but I just dont think he gets there. He should be a starter for a long time, and a good one, but not on the Brees, Rodgers, Manning, Brady level. One notch below.