The Freepulse headphones synch automatically with their transmitter, but can also synch to any bluetooth audio source (e.g. laptop) by holding down the synch button. You get the occasional 1s drop-out, but that's not a big deal in and of itself. There's plenty of bass and the range is excellent - I have wandered away from my desk and have move maybe 10m before they start to crackle - then I realised I didn't have the iPod in my pocket!

However, experience is let down by two design flaws.
The first is the proprietary charging connections which are almost but not quite micro-USB. Why, Logitech, why?! Well, I know why, but that's not an excuse. Let's hope they follow the mobile phones' example next year and move to micro-USB.
The second feature, and this is the killer - is the headband. It's too tight and resists adjustment. If you try and bend it out with a reasonable degree of force, it resists. It might be possible to permanently deform it, but I have resisted for fear of breaking it. This means you end up with a headache after a half hour or so of use. Fine for the gym (at least for lazy souls like me), but not a primary headphone replacement.

That said, the proof is in the use. How often do I use them? Very rarely, as it turns out, as my colleagues "borrrow" them quite liberally from my desk. Which is a pretty big thumbs up!