When it comes to call quality it puts in a decent, but not exactly outstanding, performance. Calls through the earpiece sound crisp and clear, but it's not exactly ear-piercingly loud, even when cranked all the way to full volume. And while callers reported that speech from the microphone was very clean and distinct, they could also hear a significant amount of background din when we were chatting in a noisy environment.
On the plus side, the headset's battery life is pretty good. Bluetrek quotes a battery life of eight hours and while it didn't quite manage to keep going for that long in our tests we still got between six and a half and seven hours from it, which is impressive.
To top the headset up with juice you plug in the supplied wall charger to the micro-USB port on the rear. Disappointingly there's no USB lead included in the box so you'll have to invest in your own if you want to be able to charge it from your PC or laptop. It takes around three hours to fully charge the battery and when it needs topping up again the headset will produce a low tone at regular intervals and the LED will flash red. Unfortunately there's no other way of telling how much charge is left in the battery. Other headsets manage to give you an indication of remaining battery life via sequences of flashes from their LEDs, but Bluetrek has not implemented this type of feature on the X3.
The X3 is a much more satisfying headset to use than ruggedised competitors like the Explorer 370. It's small, light and comfortable to wear thanks to the changeable ear hook and ear gels. The battery life is also impressive and the call quality is generally solid. However, it's a shame it doesn't include noise-cancelling technology as this would be a great feature to have in noisy environments like factories and building sites where surely this type of headset is likely to be most used.