I'm still awwed by my MS1000!! I'm so happy I ran into them on these forums. I haven't heard
any Grado's yet (no, not even MS1, I transformed them almost right away when I got them), so I'm very curious about how they sound. But I'm afraid I can't live with their low comfort.
But for now, these are about as perfect it will (ever?) get for me. Running them out of my Corda Opera with 120Ω added impedance, they also provide a very enjoyable amount of bass (a tad more than the otherwise have, running them out of amps -or portable mp3-players for that matter- with zero impedance).
I don't think I'll ever get MS Ultimate, they would sound very nice and all, but for me, I don't think I could justify buying them - with them being $600 more expensive than MS1000 and with the small improvement in sound quality. But who knows, right?

I already feel something tickling...