Arctic have used the same gray and black colour scheme for the P321 as they used with the P521. But the P321 is much simpler in design, probably a result of only having two driver units rather than the small army of them that is contained within the P521; we think this gives it a lot more aesthetic appeal.
The construction of the P321 feels a lot more solid than the P531, probably a result of removing the complicated hinges. The plastics that Arctic have used aren't the best we've experienced but most headsets we look at are more than twice the price of the P321.
The earpads are of an over-ear design and are covered in something that resembles faux-leather. They do a great job of isolating background noise – something I noticed when I saw the phone ringing but could not hear it! The underside of the headband is also covered in a very similar material.
We are glad to see that Arctic have implemented a retractable microphone rather than the oversized rotating microphone that comes attached to the P531. The sound produced is quite acceptable in terms of quality and we only noticed one incidence of distortion during our tests which we couldn't repeat.
Like the P531, the P321 features an in-line control. This lets us alter volume and mute the speakers and microphone, pause and skip between tracks and finally alter the bass level (more on this later). This is a great addition and, unlike the P531, isn't positioned inconveniently far down the cable. The lengthy 2.5m cable will be appropriate for some users but we would have liked to seen a shorter cable and extension cable.