I don't really have any problems with the
Headbanger Ear Subs' audio capabilities. The sound is great and the ability to drown out (or cancel) external noises works wonderfully. The biggest issues I had with the package were with the various ways to attach the amp to your person. Normally I would say this is something that is beyond the function of the device and shouldn't really count against the piece of hardware, but since the amp adds weight to the
Ear Subs and if not secured, has a tendency to pull the ear-buds out of your ears -- these carrying utilities are a necessity.
First the carabiner clip. It is the most secure of the three options and makes it easy to reach the amp's on/off switch, but if you need to break away from the audio device (for whatever reason), it becomes a hassle unclasping it from the metal ring and can't really be done quickly. As for the cradle clip, its problem was the exact opposite. I found that half of the time, the amp wouldn't stay clipped in and would fall out on a regular basis. Between that and the fact that when "secured" in the holster, the amps' power switch was mostly covered.
I said earlier that of the three options, I used the neck lanyard the most. That's because, of the three, it seemed to fit my needs the best -- though it isn't perfect. The amp clips to the neck strap with a simple plastic clip, making it very easy to just take off if and when you needed to get away from your PSP for a little while. Using the black box as a pendent also makes it easy to flip the power switch. Unfortunately, if you are planning on using this -- don't plan on having it hang off of your neck for any real length of time. Even though the amp weighs a couple of ounces, that constant strain can cause a little discomfort after a while.
Provided you find a good place for the weight (I recently discovered that my shirt pocket is just about perfect) and heed the warnings attached to the Ear Subs (which includes things like not turning on the Bass Boost feature on your PSP since it could damage the Subs and/or your ears), these ear phones can quickly replace any other models you might have laying around. Just give them a try.