In order to judge the performance of the headset I put it through its paces in various games straight from the odd race game to Counter Strike: Source.
First off, the headphones and USB sound card was left playing music for just about 100 hours in order to insure that it was performing its very best for the final tests.
The USB Sound card does two different modes, one native 2.0 mode where you can adjust the volume and the bass and one 7.1 virtual surround mode where you can adjust each of the virtual speakers sets individually. The 7.1 mode could turn out to be somewhat useful in games with a dull sound side because it adds some ambiance, although completely fake. For FPS games the 7.1 mode is pretty useless, it makes it sound like you are in a bathtub or ceramic bowl, definitely not good for the sound quality which you must heavily rely on in order to pick-up those small positional effects clues on the sound side of the game. In racing games such as GRID the 7.1 feature can be fun to play with, but ultimately it does not yield any advantage over a normal solution.
In regular mode the headset and the sound card sounds quite good, not $149 good, but good enough to warrant its existence. Compared to the other USB based headsets I have owned this is the best let there be no doubt about it. It is a pretty solid performing headset.
Add the fact that you have the neat little controller unit that lets you manipulate all sorts of performance aspects and mute / adjust the microphone level and you have a good all around package. So to the gazillion dollar question should you get the Megalodon for its USB versatility or the much less expensive brother the Carcharias. For me it is quite simple if you have a PC with a good sound card be it onboard or PCI the Carcharias seems like the obvious choice, you get a headset that looks pretty much like the Megalodon, has the same drivers and cup design, but without the $80 USB sound card. If you on the other hand need a headset that is versatile and can be hooked up to just about any computer, the Megalodon does the trick a bit better because it has its own sound card.
For music the Megalodon does an alright job in the 2.0 mode, switch it to virtual 7.1 and the music becomes garbled and unlistenable, unless you adjust all the other virtual speakers but the fronts to off, which basically brings you back to 2.0 mode. Compared to a set of Audio-Technica ATH-AD700s being powered by my onboard sound card the sound quality is not nearly as good, and in most games with good positional effects I actually prefer the Audio-Technica headphones because they portray the details in a much finer way.
My only problem with the Megalodon is the price. At $149 you would expect a massive improvement a normal 2 channel headset or headphones, but it really is not. It is an above average performer compared to the other USB headset but for $149 you can get a Carcharias and almost an X-Fi XtremeMusic which by all means is a way better sound card than the USB-powered Maelstrom sound engine from Razer. To sum it up you really really have to need the USB feature in order for the Megalodon to be worth your hard earned bucks.