Yes, it worked as you'd expect.
When I powered the TT on, it auto-connected to the phone (as always), then I went to speaker preferences and selected Bluetooth Hi-fi Device. I was asked to turn the Hi-fi device on (and put it in discover mode); it found the device and connected (I received the "connected" tone thru the ear buds).
Upon entering the route, I immediately heard the instruction (turn left, then turn right) thru the ear buds (the integrated speaker was silent). Upon starting the jukebox, I heard the music thru the ear buds; tapping the "next instruction" rectangle on the status bar, it muted (or is it paused?) the music to play the instruction.
Further, I then tapped the screen, then "mobile phone", then "call", typed 555-1212, then "ok"; music was paused, the BT Hi-fi device made the "disconnected" tone, the integrated speaker took over and I heard information say "What city, please?" When I hung up, the music started playing thru the integrated speaker on the TT, then the BT Hi-fi device made the "connected" tone, music switched from the integrated speaker back to the ear buds and instructions (turn left, then turn right) soon followed.
The rest of the trip went smooth, music played without stutter or skip (which sometimes happens when I get too far from the BT "transmitter" at work) and the sound quality remained high.
(hope that was not TMI)