I think honestly the main thing it would do for me is keep me from regretting that I didn't buy the fastest available processor--from a purely idealistic standpoint, anyway.
You got that right! I really don't need the CPU boost, but I'm planing on getting the 15" rMBP with the 750m and a 1TB SSD so I don't think I can stop myself from getting the 2.6GHz.
----------
And do the 2.6Ghz models have a lot of yellow screens? Why did you mention that?
No, not any more then the others, it's all luck. I think Starfyre is saying get one and leave it up to chance, get one model and if it has a bad screen return it and get the other model.