My friend.. the Q701s are indeed a very good headphone, arguably better than my K701s, which have a slightly lighter bass, but retain the very good mids and the highs should be the same, or ever so slightly more present. Regarding the comfort, it does (since its absolutely the same) require getting used to.. if you have a big head like me! However they become very tolerable, if not comfortable on the long run.
I think your MAIN problem is driving them! Driving them from your sound card on the laptop/pc can make the bass muddy and overpowering the music. It is really bad. With these cans you need a decent-good amp. You will have to part with some 200-300 usd. This will certainly make the bass tight and sharp, bring the mids forward, and tame the treble!
Do not sell them for a crappier pair of phones, it will be a mistake you will regret a lot! Regarding improvement in SQ in the 300-400 usd range, i dont think it will be very significant w/o an amp!
I dont know what are the prices in the US, but the retail in Europe on the Q701 is 400 usd, and on the K701 is $350. So for me, they are pretty much in this range! The reason why they are cheaper in the states, is I suppose the reduced demand. In Europe, they are very highly regarded.
.
Some people say that the HiFiMAN HF-400 can be driven from anything without an amp. Even the company states that. (check it out)
http://hifiman.us/Products/?pid=115 It costs $400 and since HiFiMAN is considered a high-end company, I would suppose they are better than the K/Q 701. But they also lean on the warmer slightly bassy side.
However, i doubt it after I saw the sensitivity that you can drive them from an iPod or even a Laptop SC without distorting the sound.