When 7.1 first came out a few years ago I spent an inordinate amount of time listening to 5.1 vs. 7.1 for movies and some classical music. For me 7.1 is modestly better and IMHO it's enough better to go the extra 2 channels if you have room. At the recently concluded CES I saw the Theta demo of Auro 3D With height channels and the Dolby Atmos with 7.1.4. Very impressive. If you can swing your bigger room, go for it.

Gary

My Kit: Trinnov Altitude 32,Oppo BDP 203, Sony 600es, Martin Logan Neoliths Mains with VTL Siegfried II's, ML CLX's, ML Renaissance, 5 ML Theaters,13 ML Vanquish, 6 ML Edges, 6 ML Axis' 8 Velodyne DD-18+'s, Pass Labs 600.8,Pass Labs 160.8, Pass labs 160.5, Bryston 14B-SST, 6B-SST,6 Bryston 9BSST^2's, 14' Stewart Screen, Berkely Alpha DAC RS