I have a pair of iGrado's. They sound alright.
I would not recommand them though. The quality/execution is not that good. I don't know how good or bad the SR-60's are, but the iGrado quality makes me intend to think the Grado fame is overly hyped.
I understand everybody has different ears, what sounds mediocre to me might be the greatest sound to you. But now get this: the foam pads inside the housing (under the grill) have different density, I mean the left pad is about twice as dense as the right side one. Thickness is about the same, just much more dense material. Why is Grado doing this? I have two guesses:
1) their pad supply quality is inconsistant, and Grado didn't notice this very obvious difference in pad property when they install them into the iGrado's. Or maybe they just don't care. That would say something about the iGrado quality control wouldn't it?
2) Or they did it intensionally, why? to force the left side sound slightly louder I would guess. If the left/right drivers sensitivity are not
selected to match each other, then by using different density backing you can force match the L/R to sound "about as loud", so the sound image can be centered. Still, non-matching drivers makes, well, non-matching phones. You can force center the sound image, but that different backing also yield different frequency response to the L/R phones. Makes me suspect Grado could be making iGrado's using leftover sub-standard drivers after they selected all the "matching sets" for the SR-60. If this is true, then the iGrado's are intended to have much lesser quality than the SR. If this is true.
Anyway, from this observation of mine, I'd say if you want the real Grado quality, pay more and get the SR.
I am ok with my iGrado though, I took both foam pads out and use iGrado as my guitar phones (my guitar amp is mono anyways)