I have to admit that I don't believe that this is true. I own the Astro a40 Headset, and it's a Godsend for directional audio.
When I play 360 games with friends, I always use these headphones. The Dolby Headphone is crazy accurate when playing Modern Warfare 2. I have been saved by these headphones many times, especially when people sneak up on me. I almost always get that accolade that says I never get snuck up from behind, haha.
I'm not a basshead, and the closest thing to bass I have are the JVC Marshmallows (which I did the Kramer-mod), which I use only when I have to. I enjoy the bass that comes from these headphones. They don't over power, but powerful enough to make a AC3 concert or action scene on DVD sound like a blast. I have powerful bass in my home theatre speakers and my friend's even better theatre speaker setup, and I'm only annoyed by it.
HEADPHONES PROS/CONS
PROS: I'll take some from Punisher
1. Confortable open air design that you can use for hours
2. Mic is detachable and crystal clear
3. Good Mid and Highs
4. Manageable Lows
*Here's a fix for mic volume: move it to or from your face for optimal volume!
5. Very nice looking.
CONS:
1. Very pricey
2. All the cords can be a little annoying
3. Messes up my hair when I wear it for a while
4. Obviously not the quality of headphones over $300. Not really a con. You paid ~$200.
MIXAMP PROS/CONS
PROS:
1. Dolby Headphone, large sounding space, and doesn't give me a headache after listening for a long time.
2. So many connections, and the Pro Logic means that I can get Dolby Headphone from stereo sources (except 3.5mm)
3. Portable and very good design.
4. Because of connections, compatible with almost everything.
CONS:
1. Cords again. Lots.
2. While portable in a house, it's certainly not something to walk around with or sit on a bus.
3. No DTS decoding, yes, but these are mainly for games and sometimes music and that only uses AC3 files mostly.
In my summary, I don't think they're the greatest audiophile headphones, but the sound is still great and comparable to nice headphones in the same cost range. And since it is a headset, it has the added bonus of a great sounding mic, an Amp that is full of awesome features, and a really pretty box. In the end, I think I got what I paid for.