Bought for myself the 560 and just bought this one (540) for my son after he started to take mine too often. Because he use it more outside than I do, the small (540) is a lot easier to use and to put in his schoolbag.
Bluetooth pairing works really smooth and after few weeks I cannot complain about how it function or how it is built. Goes around my big head without problems.
Nice purchase and really practical without wire.
PS: The battery does a good job for over a week between charges with (1-3 hours of use per day).