Soundstage isn't anything special, larger than other closed on ear portables I've tried but smaller than almost any open headphone (tho low end Grado's have a rep for shallow sound stage too so it's all relative). The sound signature is very different from Grado's, are you looking for something similar or what?
Edit: Saw your other thread, personally I find IEM more comfortable to sleep with on a nightly basis (you can roll or turn easily if you get small ones that don't stick out), and I've always got one old pair of cheaper IEM that I use for that (mostly when staying at someone's place on vacation). They often end up dislodged from my ears by morning but since it's a cheap old pair I don't care if I've tangled or pinched the cable... That being said, several people in that thread did say they sleep with their M-80 (including an ex soldier?) and they're durable enough that they might hold up if you don't toss and turn much, plus the cable's easily replaceable.
Far from optimal IMO tho... KSC75 on a sweat band might work (as mentioned in the other thread). They're open but the beanie would muffle most of the leaking so it might be closer to the sound you want. I have a pair with the clips removed sown into the pockets/bend of an American Eagle beanie for winter use (this beanie's actually made for this, just came with some crappy phones I replaced).
Edited by Impulse - 3/28/13 at 11:24pm