Haven't used it myself but...
Everywhere I've seen comments about it they've all been negative.
It appears the quality is "so good" that it picks up everything.
Somewhere I've seen where Mitel is suggesting that you get your users to just "use it for a while". They're apparently suggesting that once people get used to it they really like it. Don't know about that. Never seen where anyone has gotten through the "use it for a while" stage.
Ralph