Pros: For the money, one of the better headphones. Compares favorably even to beats. Excellent, powerful bass. Does not leak sound
Cons: Fragile. Cord is extremely thin, and susceptible to breaking (as mine did). Slightly sacrifices midtones and trebles (not "sharp")
The JVC HA M750's were my first "real" pair of headphones. Previously, I had just used iPod headphones and cheap 10 dollar headphones from my local grocery store. As such, I was very impressed by them. When I turned music on full volume, you could feel the cans shaking - a pretty cool experience that even my ATH M50's can't match. Interestingly, I originally got these headphones so that I could play video games, not listen to music...but here's the perspective for music...
The bass on these headphones is phenomenal. Definitely its strongest suit. However, the trebles and the midtones suffer - so these are great for Rap/Hip-Hop and Dubstep. They are definitely not as sharp as the ATH M50's (which I'll reference, as they're really the only other headphone I have experience with). Where vocals feel crystal clear on the Audio Techicas, these lack the clarity that really makes my other pair stand out.
With that being said, the audio quality is still excellent. I compared them to beats which my friend had, and honestly thought they were better (although quieter - but that's because they don't have batteries in them). They also do not leak sound at all. Given the fact that I was upgrading from iPod headphones, these were a huge and VERY noticeable improvement. It sounds cliche, but I noticed hidden tones in music that I had never heard before! Thus, audio quality is very high. Yes, bass is overpowering. Not as bad as beats, but it's still strong. But truly, the tradeoff is quite minor, and to be honest, the fact that they aren't as good as headphones 3x their price isn't surprising at all.
The pads on these are extremely comfortable, but very small - so your ear is constantly pressed by the cup itself. Thus, the headphones grow very uncomfortable after 2-3 hours. Given the fact that I am a debater who has to spend 6-7 hours researching at a time, that's a huge minus.
A big plus of these headphones is the price. They look excellent. They sound excellent. And they are only 50 dollars! I think that they are probably one of the best steals for 50 dollars on the market.
Finally, the big problem: durability. The headphones themselves are fine, but the cord is extremely weak. It is only a bit thicker than an iPod cord, yet feels more fragile. My headphones actually broke when the cord snapped, after fraying, even though I took great care of these. I always put them in a plastic carrying case, but the cord still frayed. They lasted a year and a half.
Verdict: Buy these, but take great care of them.