They work as advertised...
I haven't had any of the problems some of the other reviewers complained about. I did set them on a snare drum and they fell off that and when they hit the floor they broke, but I can't knock them headphones for my mistake.
Sound is decent, nothing you're going to get blown away by. The cups fit snugly over my ears and do a good job of isolation unless I tilt my head at an awkward angle, like when trying to see where a dropped stick may have gone off too. I wear eyeglasses at all times, and even though the fit is snug it isn't bothersome. I also have a huge head, and these manage to fit me, so unless you're a giant, they should fit most people.
The isolation is what you would expect from over-the-ear ear protection. The lows tend to come through more, which I don't mind with drums. They cut out the cymbals and more cutting tones of snares, which is where you get most of the damage from anyway. (As a side note, when I jam with people, I'll use both foam ear plugs and then put these on and everything sounds amazing! Nothing is overbearing and it's like hearing an EQ'd mix live!) I do plug them into my phone to practice with a click or to play along with tunes and I never have to crank the volume completely up.
Given they are headphones, they will have the same drawbacks all over-the-ear hearing protection has. They do squeeze to give a tight fit. I'm good for about an hour to an hour and a half before I feel like I need a break. But before that problem sets in, I'm usually getting pretty sweaty from them. The plastic wipes clean easily though. Also, whenever a rogue hit goes astray and I've struck one of the cups with a drum stick it took it just fine.
The cord is sufficiently long for my purposes. My headphone amp is about four to six feet away and I have no problems reaching it with the supplied cord. It also came with a 1/4" adapter, which is a nice touch.
You won't be mixing with them, but that's not why you buy these. They offer great isolation, decent sound, and will fit a big noggin. The cord length is decent. Just don't drop them! Only thing I'd like is if the price came down just a little. Not sure they warrant the current cost. I think $50 is about right.