Pros: Isolation, Fit
Cons: Fragile stock wiring
I purchased these headphones on a whim for use at work. I was working (at the time) in a production warehouse and frequently outdoors calibrating product.
Often I spent my entire workday isolated and would wear these for 8+ hours multiple times a week.
Within three months (of admittedly very active use) the stock wiring at the plug had broken but a quick resoldering to a much nicer plug has resulted in setup without a single hiccup since.
Highs are clear, mids are distinct and the bass is crisp. I have never run these with a DAC or amplifier (just starting to dip my toes in the audiophile waters) but driving these from my cell results in a very pleasurable listening experience.
I have read that some people have issues with the fit but for me there was no problem at all. There are two different ways to wear these headphones, either with the wires wrapped back over the top of your ears or with the wires dangling (like most cheap earbuds).
I usually wear them wrapped over the top of my ears and this probably helps with any physical listening fatigue from the weight of the wires. When wearing them like standard earbuds I find that the music loses much of it's quality because the headphones are oriented in a manner that directs audio differently down the ear canal. The easy remedy is to simply wear the left headphone in my right ear and vice versa. I realize that this isn't the intended use but doing this results in the same listening experience for me.
So in conclusion, from some average lay-person perspective, these are some great headphones. In hindsight I realize that I could have probably invested in better headphones for the price I payed, but I am very happy with the purchase.
I actually don't own these anymore, though. They were stolen while I was traveling abroad. I've been reading through head-fi over the last few weeks trying to plan my replacement to these headphones and I'm excited about taking my next step into the world of high fidelity audio equipment. I've changed careers and am purchasing for mostly at home or travel listening so I think some over-ear headphones will be next. The ATH-M50's seem like something everyone should own but the appearance of those JVC-S500's (or S400's) is extremely intriguing to me....