Because this Invisio G5 Bluetooth headset is the world's smallest Bluetooth headset, there's probably only one big reason why you're buying it. You don't need a test to tell you that it's the smallest headset. But you do need a test to tell you how well it feels in your ear and how well it handles call quality.
On both these fronts, the G5 performs admirably, and Symbian Guru says most of the time the caller didn't know they were actually on a headset. However, the noise cancellation isn't all that great and if you're talking in a car with the windows down the other side barely be able to hear anything. There is noise cancellation (he said you can hear just fine in a big, noisy warehouse), but if you're looking for performance over size, you'll have to shop elsewhere. [Symbian Guru]