Prime Froch would beat the current Golovkin. The Golov of 5 years ago outclasses Froch after having problems with his size.
According to his fans, ggg got past his prime exactly at the same time he finally fought some decent opponents
I've always said this is a very tough fight for Golovkin, just because of the strength and size of Froch. Froch has a good jab and his reach is huge. GGG will have to take some shots to get inside.