I still believe that Griffin III is an elite prospect in most drafts, and I still believe that Luck is the top prospect in this draft, but there is no doubt, IMO, that
a) RG3 throws a better deep ball
b) RG3 has a better arm
c) RG3 has more upside.
The question for me is whether or not RG3's upside trumps the preparation and development that Luck has had. To me, Luck's upside is elite enough to compensate, and thus I think he is better.
I will challenge some notions, though.
a) Luck doesn't have average arm strength - his pure arm strength is clearly above average, and he can easily heave a ball 50 yards without torque, and it can go further when he puts his body into it. The issue is
i) Cosell does note some mechanical flaws, and I certainly don't have the time to study.
ii) I've always had the feeling that he tries to "touch" pass the deep ball when the deep ball isn't the first read.
b) He has more than enough velocity on the hard intermediate passes outside the numbers.
Because he ran such a complex offense AND because he had such freedom at the line of scrimmage, I think he checked out of a lot of throws that most QB's in college would've chucked. As a result, there's a lingering feeling that he has poor or average arm strength. It certainly isn't an elite arm, but reading the Pennington/Rattay comparisons is just ... off, IMO.