2013 didn't offer any new earth shattering features except maybe dual hdmi video feeds (Denon X4000/Yamaha A1030) at a level below flagship. 2014 does though. Hdmi 2.0. The ability to pass 4k video at 60 frames per second (broadcast tv rate). Might be a few years for it to actually be useful though. No 2013 receiver has 2.0. They do have 4k @ 30hz with hdmi 1.4. No new audio features coming this year.