A short and crappy review
Just got them today. Thanks again!
I'm comparing them to my PortaPros now...
To be oversimplistic, I think they sound fairly similar straight from my S9, sharing a rather warm and bassy sound. Though this may change as the iGrados burn in, (my PortaPros have a lot of hours on them) I think the PortaPro barely has the edge simply because they're a bit more detailed, have better separation and better highs, whereas the iGrado has somewhat recessed highs (though smoother than the PortaPro), a bit muddier bass, and most importantly, doesn't seem to have the same liquid-like, famous Grado mids. Essentially, from what I can tell now, the iGrado is a great portable can, but doesn't really retain the "Grado gene" that I love so much.
EDIT: Nevermind all of that. Upon other suggestions, I just did the nickle mod--Much better sound indeed. Better than the PortaPro, especially in the mids. The detail in all registers, especially the highs, came out really well and no more muddiness either.