in my car I got a Parrot CK3100 with my Samsung I9100G. The audio quality with this combination is quite bad on the side of the listener.
I am told, that my voice comes cracky, there are a lot of interuptions and so on. Actually a normal talk is not possible.
When I connect an old Sony Ericsson W880 the audio quality side of the listener is much better, normal i would say, in comparison to other systems that i heard yet.
Overall, the sound quality on MY side is always quite good, in the car i can hear everything quite well.
On the S2 i had different custom ROMs, but no significant difference, the Parrot has the latest firmware.
Is this a problem of the bluetooth version or really phone (hardware) depending?
Thanks for sharing your experiences!