I've flown with my new 740b 4 times now and I have to say I really like it. They seem to have really put a lot of thought into its design.
Regarding the playing of music, the only way that I can see getting to the music controls is exiting the map but run it in the background, then press a couple of more buttons. Finally I'll come to a screen where I see the music controls (pause, skip, volume, etc). Is there a shortcut to the music player controls that I'm not aware of? During approach and landing I like to shut off the music but that's not a great time to focus inside the cockpit. A quicker way to get to the player controls would be great.
Also, the shuffle algorithm is a bit weird in that sometimes it wants to play the same 3 songs over again before proceeding to the other songs I have loaded on the unit.
These are all minor nits. As I said, I really like the 740b.