What I do like is the "Blendr" stem mount that comes with the 7.3 and up. Lets you put a light or a bike computer, phones, etc. on there. It's just nice not to have to buy a seperate accessory to have your phone mounted on your handlebars, and it's integrated unobtrusively into the stem.

I'm starting to get a bit Trek-preachy here but I really like what they're doing with these 2015 bikes.