With dGPU's usually being more prone to issues, producing more heat, using more power (and thus lower battery life) I'd consider the 15" once it ships with iGPU only. I think the Iris 580 would perform very well, considering how well the Iris 550 is doing. The Iris 550 is a 48 EU part while the Iris 580 is a 72 EU part. The previous gen 15" shipped as iGPU only models. What do people think the chances are of a 2016 15" iGPU only model? Obviously we'll have to wait for Intel to release the appropriate CPU, but i think it would make for a great laptop. This is however not a thread for bashing on dGPU's, as they are very good for their use.