2011 macbook pro 15" performance on League?

Hello guys, I am looking at getting a 2011 macbook pro to play League of Legends on. These macs have i7 CPU and the radeon 6750m/6770m GPU in them so they look to be pretty decent for gaming and they are getting pretty cheap now days. Anyways does anyone have one or can anyone tell me if league will be playable? Thanks!