Bluetooth lets you connect to most mobile devices as well as PCs and laptops, which makes it really convenient. But it's also low-bandwidth and slow, which means it may compress the audio (and thus make it sound worse) and introduce delays between the device and the headset. The delays, referred to as latency, can range from just annoying to game-ruining, depending upon how important the audio and your chat is to responding quickly. Bluetooth also requires that there be a pretty small distance between the headset and device it's connected to. The best wireless gaming headsets come with a USB wireless adapter, usually 2.4GHz, to create a dedicated, fast, high-bandwidth channel between the headset and the system, and one that can maintain the connection over a larger distance.