It has always worked exceptionally well for me mss-ca on every berry I owned. They did however do away with the audio boost option in os 7.1, but I have not missed it!
mine is kinda bad too i have a feeling it is the position of the microphone and how i speak into the phone or the case perhaps getting in the way but i was told i am more clear when im on my older bbs
I'm using OS 7.1.0.267 on a Sprint Bold 9930 (yea I know) and my call quality and reception is better than my my previous BlackBerry devices hands down. To the OP, is their anything that you don't have problems with on your......9700??( device info)