the GPU in the 15" rMBP (any build) dominates the 2010 handily. I went from the 2010 which was 'okay' to ultra settings native, and when I say native I mean: 2880x1800.
it really is that good. I've owned powerbooks/mbp's since the beginning, and this is the first real GPU they've ever put into a notebook/laptop. It's not crippled, it's not under clocked (it's clocked very high), it isn't your typical gutted mobile GPU that Apple seems to like putting in their devices.