If nothing really bothers you, then what is there to upgrade?
10 speeds to 11 on the rears isn't a big enough deal for me. Electronic shifting.... maybe, but then if you can't get all the extras like battery and stuff in the frame out of sight, it's ugly (pronounced you-glee). Expensive too, buy a new bike for that.
That leaves you with wheels. Are you going to get any bang for the buck spent? How much lighter can you go from what you already have? Save for a new lighter bike and you'll get more bang for your buck IMO.