That is one "impression" test that I'll be looking forward too. For me, personally, I just wish I could have gotten used to the extra weight of my SR-325i Grados. I couldn't ... really, so ventured down the wooden road. Though, I'm sure we're bound to read about your various differences that you've spotted and have heard between the use in an aluminum cup vs. a wooden cup. For my own selfish sake, I kind of hope the aluminum combination doesn't trump the wooden cup option - because, my whole thought process could be recycled again ... and, then I could be obsessing over what I could get out of the Aluminum cups and aluminum air chambers with the Magnums.
I little part of my mind wonders if someone from Grado Labs has ordered a pair of Magnum drivers to see what all the "hype" is about. I'm pretty sure that they monitor certain message areas to ensure they have their hands on the pulse of things with their company. It would be interesting which of their cups they'd select to test them out with. I'm sure Grado would be proud of how well someone such as Rhydon has taken a component of theirs, yet modified it appropriately so it's a worthy piece - and, still fits into the rest of the Grado headphone structure.
Amazing stuff.