I also have really enjoyed my Jump to AKG from my Audio Technica AD700. I just bought a pair of Q701s. They really do solve any lingering comfort problems I had with the AD700; though those were pretty comfortable and light, especially more comfortable now that my earpads are well broken in so the bottom edge doesn't press more on my jaw than evenly around my ear, my the Q701 actually rests on my head with my ear not being pressed down by any part of the pad. The Q701 is truly circumaural. It is also more even through the frequencies. The only thing is that it's still just about as warm as the AD700s... Probably can't do any better with any headphone than these two thermally, so just remember that it's summer and give your ears and headphones a few minutes of break every hour. You don't want to damage your hearing anyway.
The Q701 was about twice the price of the AD700, there's no denying that the AD700 is a great value, but the upgrade has been worth it to me. The comfort and SQ quality increase is noticable, but not 2x as good. For me, however, it reached a level where every checkbox on my list (besides "good for train/Airplane commute") is checked. I dont make much money, but I simply saved up for a month. In your case, if you don't think spending 2-3x as much money is worth it, then perhaps consider a model lower on AKG's full-size lineup like the k240 series (K240MKII comes w/ spare cable & 2 earpad types) or a Beyerdynamic 770. The general consensus from what I read when I bought my AD700 was that it and the Beyer's were the kings of fit comfort.
Knowing what I do now and if I wanted a "first high-quality headphone," I would get an AKG 240 MKII. It's semi-open, so it'll leak less sound as a bonus compared to your AD700, while still sounding quite airy. It also doesn't require a dedicated amp, though it would benefit from one if you want to upgrade your sound in the future. So many producers mixed their albums using these headphones and their predecessors that you're going to hear what you were intended to hear. The only possible downside is, frequency wise, it has a bit of a bass boost from neutral - nothing extreme, but at max +9 Db which I find is the limit before bass starts getting muddy and overpowering. You may actually really enjoy the fuller sound in contrast to the AD700.
