So I think I'm getting hit by upgraditis. Been using the AD900s for 3+ years, easily thousands of hours, amped, unamped, with tube amps, solid state amps, and with different sources. They were my first quality headphones and will never be forgotten. Build quality is astonishing, they have lasted extremely well, have not replaced the pads yet even though they are pretty cheap. The pads don't even look very worn, perhaps a little "flatter" than they were when new. The soundstage is huge, sound clarity is great, bass is unobtrusive. But as you do, I'm starting to wonder about what else is out there. I don't know what to get next, but I do know a few things. They need to be MORE comfortable than the AD900s. Yes, the AD900s are comfortable, but I do very long sessions (3-4-5 hours regularly) and I have a big head, so things do get uncomfortable around the ears. I do not find them heavy, and the wing pads on top of my head feel great, but the ears do get uncomfortable. I have tried the HD800s and found them more comfortable - I think it's because nothing touches my ears.
I will be using them mostly with a PC, for movies, games and music. Budget-wise I'd consider up to $2k - this would need to include an amp and sound card. So what have people moved up to, from the AD900s?