So, here's my story: I happened to be shopping at Target the day before my international flight (17hrs of flying) and saw these headphones. The price: roughly $30 was the largest plus for noise canceling headphones. I had heard bad things about noise canceling headphones, but for 30 bucks I figured I could take a chance.
Feel: First of all, they feel very comfortable inside your ear unlike many ear buds I've tried. They also fit well, with three different size silicone tips.
Sound: Going into it, I knew they weren't going to sound great. I'd heard that noise canceling headphones usually leave something to desire in the high and low range. These headphones are acceptable, but not great. If you like listening to music with great equipment, you will be disappointed. But...
Noise Canceling: What the noise canceling system does is add some sort of soft white noise to the background and enhance the music you're listening to. Normally when you're in a place with a high level of ambient sound (i.e. airplane) you have to turn up the volume very high in order to hear what you're listening to. Sometimes, in order to hear everything, I have to turn the volume up so loud that it begins to be a bit painful (at least this is my experience). With these, I didn't have to do this. I can listen to whatever I'm listening to at a comfortable volume. The sound is full and clear and helpful. It works great! I don't really know what the other reviewers were expecting, but perhaps they forgot to put the battery in. These babies helped a lot on my 17 hour flight. And it doesn't use up batteries fast.
Problems: It's true, the battery case is in a very inconvenient place. However, I mostly use these while sitting, so that doesn't bother me. Also, the cords get easily tangled.
Conclusion:
So, for the price, they are very much worth it! Perhaps there are better headphones than these, I haven't tried any other. If you're expecting headphones that silence the outside totally, you're not going to find them. The only other option I've heard of is Etymotic makes headphones that work sort of like earplugs and supposedly sound great. But they're over $100. For $30 or less, it's a no-brainer...