depends which stats you look at.

Grossman > Manning
+ overall QB rating
+ TD passes (10 vs 8)

Manning > Grossman
+ air yards (1278 vs 1243)
+ percent completed (62.0 vs 60.4)

you just gotta remember, Manning's offense is designed to throw the rock. 171 attempts vs Rex's 152, a 19 throw differential ... figure if Grossman threw the ball 19 more times, I'm sure he'd have more yards than Manning.

Either way, the fact this is even a feasible debate, I'm thrilled.