I'm sure you can find a thread outlining any "problem" that you want to have, if you look hard enough.
I am on AT&T and the call quality is great....strong sound, speakerphone is good, etc.
Just enjoy your phone and quit being neurotic about it when you don't even have the phone yet. So you ordered the phone, haven't even used it for yourself, yet you are worried to make sure that the new JB update "fixes" a problem that someone else thinks they have according to a thread on a chat board.
My guess is if you hadn't read the board and just used your phone, you wouldn't have found any issue with call quality. There are millions of units out there and if call quality were a major problem, believe me you'd be hearing about it ad nauseam on this board and others....