There is a pretty severe, widespread Android Jellybean bug that causes Google Now voice search to not work over bluetooth audio (it gets stuck saying "Initializing"). I've personally dealt with this on a Galaxy S3 and a Galaxy Note 2, both running 4.1.1.
I'm curious whether the Razr Maxx HD has this bug - is there any credible information on which phones are affected by this bug? Or can anyone vouch from experience whether this is a bug on the Razr Maxx HD as well?