I have had a few headphones over the years, until I finally settled on the Grado SR325i. I am using a grado RA-1 amp (battery powered) and while the sound is the best of the sub-$400 lot, the problem is that they are a pain (literally) to wear for anything more than a couple of LP's. So I've decided to move on. I'm looking for headphones that are light on the ears (especially for those of us who wear glasses), have a lively sound (not too dark), and excellent bass response. I picked the Grados initially because they had very good 18-24KHz. range and a lively presence. My budget is about $500, but I am willing to buy used as well.

I've been considering the Beyerdynamic DT880s and the AKG K701s, but I'm open to other models. What I need to know, since there is no one place where I can try these on, is if these are comfortable for long listening sessions.