Just thought I should share this information.
For my F700bt, the quality of bluetooth performance is tied directly to the state of my phonebook. When I sync my phone with the F700bt without editing/scrubbing it first on my computer manually, I get TERRIBLE bluetooth functionality/performance. (There are many other posts on this forum that tell "How to" edit the phonebook.) I can really understand why so many people hate the bluetooth function of the AVIC.
Here's what I experienced:
1) Sync old RAZR with HU: Slow bluetooth, no voice dial, unresponsive (hangs), only a portion of names transferred properly.
2) Manual edit RAZR phonebook: Voice dial work great!, Bluetooth responsive, no hangs!!!!
3) Retire RAZR, Sync new W760a: Entire phonebook transferred perfectly, BUT Slow bluetooth, no voice dial, unresponsive (hangs).
4) Manual edit W760a phonebook: Voice dial work great again!, Bluetooth VERY responsive, no hangs!!!!
NOTE: On manual edit, must remove all non-alpha numeric characters ("), $, &, /, -", etc.). I used "&" and ")" in my phonebook (I sync my phone with Outlook), so these where causing me problems.
This scenario reminds me of what happens when I try to open a corrupt database or spreadsheet on my Windows laptop. It causes the entire system to run slow or hang. Much like the response of my F700bt.
Hope this helps someone!