Sennheiser audio quality, with a bit meh but still above average mic, (wireless bandwidth limit I assume).
What really makes these my favorite wireless pair ever, is the truly insane battery life. 100 hours, enough that by the time you get the low battery warning, you can still finish gaming for the day, and the next, and then plug them in to charge. They go into standby on their own, I’ve only ever touched the power button to turn them on the couple times I completely drained the battery.
What do you mean by surround? Headsets either have good stereo or they don’t. Are you referring to virtual 7.1 surround that basically all cheap gaming headsets advertise? (it doesn’t work, there’s a reason Sennheiser, an actual audio company, doesn’t bother) I have never once used the feature on a headset that supports it. You have two ears, the headset has two speakers. Either the game has good positional audio or it doesn’t, some extra processing in the middle has never been able to fix that imo. The GSP 670 seal well and positioning footsteps or gunshots has been easier than on any previous set I’ve had.
And they work perfect on linux, they use a usb dongle and are detected like any other usb audio device.