Benn would lose, he was too easy to hit at 160 and anyone that can bully GGG around could do the same with Benn who was stopped by Watson and Eubank at 160.
Benn stopping Derev in one or two rounds honestly wouldn't shock me, but I think Derev's late surge wins him a hard fought decision, in an awesome fight.
I think Benn hits hard enough to put anybody away, and Derevyanchenko has been dropped by big hitters before. However, SD fights close up and likes to offer angles. Benn will have problems with this because he's denied space for leverage and its going to be hard to get set for the big bombs. I think I agree with George. Benn will start strong early, but SD probably hangs in there and grits out a win late.