I don't often receive many complaints on the BT quality from people I am talking to.
However, the BT command system itself doesn't understand a single thing I say except for "Dial by Number," haha.
Once it asks me to say the number it doesn't matter how fast, how slow, over-enunciated, or loud I say the number, it will come up with something off the wall, or just come back with "Pardon?"
Literally, if I say 555-238-9410 if it understands me at all it will say "3102, is this correct?" or something as equally ridiculous.
I've relegated myself to dialing manually through the phone and letting the BT pick up the call.
The sound quality of the BT 'robot lady' is horrendous as well. When she gives commands or asks questions it sounds like I am on a very low reception phone call with her, not just listening to a computer play a message.
Pretty annoying, especially coming from a BT system in my former 2010 Mazdaspeed3 which was wonderful.