In terms of comfort and design, the Ear Force X4 headphones are a bit heavy on the head. While the ear cups and headband are cushioned and comfortable, they may feel a bit weighty over an extended period of playing time. On the left ear cup is where you'll find the controls and ports, including a volume adjuster, power button, bass boost, and the port for the chat adapter that hooks into your Xbox 360 controller. The left ear cup is also home to the flexible microphone boom. We really liked that the boom is detachable, as it can become distracting when not in use. The right ear cup is where you'll install the two AAA batteries. Turtle Beach includes a pair in the packaging and claims they should work for at least 20 hours, but we do recommend getting some rechargeable ones.
In terms of sound quality, we were impressed with the overall channel separation, considering the headphones house drivers in each cup that are a mere 50mm in diameter. During our trial with BioShock, we could easily tell when an enemy was behind us. The leaky underwater city allowed for dripping and splashing to be heard all around, and the headphones did a great job of maintaining that surround-sound effect. Our only complaint with the headphones is that they don't really allow for complete noise reduction or isolation. If there is other sound playing in the same room, you may notice it more than you'd like.
We enjoyed having a volume adjuster on the side of the headphones, but didn't really notice much of a discernible difference when turning the bass-boost switch on. It does add a sliver of richness, but it's not drastic, by any means. If you're concerned with maximizing battery life on the headphones, we'd recommend leaving the feature off.
Our experience with using the X4s to chat during gameplay was very good. Incorporating chat requires you to connect the headphones to your 360 controller via the included wired adapter. This is almost exactly the same adapter that is on the end of the Microsoft-branded headset, complete with a microphone mute switch and volume wheel. A wireless solution for chat would have been ideal, but we'd imagine this would severely compromise battery life on the headphones. While we didn't necessarily notice it in action, Turtle Beach claims the X4 contains an autoadjusting chat-volume feature to compensate for noisy gaming sessions. Regardless, there was never an issue with hearing anyone during our online play with Rainbow Six Vegas 2.
Overall, the Ear Force X4 headphones provide a great-sounding experience for playing games when using external speaks isn't an option. We'd imagine a few gamers would even prefer the X4s, regardless of the situation, as they provide accurate 5.1-channel surround-sound effects. Similarly, this is certainly a well-advised alternative for those gamers who don't have an external surround-sound system. The X4s' $200 list price is a bit steep, but with online prices closer to $180, you could think of it as an alternative to buying three mediocre games. And, when you consider that the Ear Force X4s are compatible with almost any source, they may be the only wireless headphones you'll need for a while.