Congrats on your TE. I really like mine.
Depending on what you're used to, the JBL/TomTom Nav stuff can be infuriating to use. Taking the time to read the manual paid off for me. It's still a little annoying, but not nearly as much as it was. No need to read cover to cover, but once you discover how you want to use it, look up the functions you use to see if there is a better way.
Note: no voice commands work when you turn the screen off. :-/
Coming from a six year old Garmin unit, I still think the TomTom stuff is behind in terms of how clearly it explains highway exits or complicated intersections. There are options to set how it routes you which probably also fix some of the scenic tours the unit is apt to take you on.
On the plus side, the sound is nice (nicer with some key speakers replaced with Infinity aftermarket speakers). Experiment with party mode, which seems to route full power to the sub, and turn on your rear hatch speakers. It probably changes the amp output too - sometimes it sounds nicer, other times it's really really boomy.