If you've been used to a built-in system, as I had been in my Nissan (also a Parrot system), then this is something of a disappointment. I find it clumsy to operate and having it attached to the sun-visor doesn't help when you want to answer or place a call whilst on the move. Muting/pausing/switching off your stereo, then reaching up and trying to find the right button to answer a call by feel, whilst keeping your eyes on the road, isn't really a very safe manoeuvre. It would be much better if you could answer a call by saying "Answer".
On the plus side, the speaker is surprisingly good, although my car is pretty quiet. If you have a sports car, or convertible, I would think this unit would be hard to hear. Apparently, the call quality at the other end is very good (according to my wife). I have found it impossible to update the firmware with Parrot's software application - it just freezes whilst flashing. Maybe because I am using Vista. I have asked Parrot technical support for help (they are generally pretty good - I have had Parrot units before and they were very helpful). Pairing with my iPhone was a little cumbersome I have to say, and I haven't managed yet to pair with my wife's N95 - it just won't do it. It automatically picked up the address book from the iPhone and so far, voice dialling seems to work OK, at least for the contact name - oddly, I have had to repeat "Home" or "Cellphone" many times to get it to recognise that. However, if you have contacts with foreign names, I think it's going to struggle.
Ultimately, I think I'm going to buy a Parrot MKI9200 and wire it in. I generally believe that Parrot is the best Bluetooth car-phone system, and this unit is probably good value for money at its price point, but I just wish I'd gone the whole hog from the start.