Except for having no surround backs, my 5.1 speaker setup is all reference II, with the exception of a Velodyne 12" Subwoofer. the fronts are RF-7 II's. These are all pushed by an Onkyo NR-808 7.2 A/V Receiver. I asked for advise here as to whether or not I should undo my bi-amped fronts and add in surround back speakers. Bi-amping the fronts uses the surround back connectors and makes the setup 5.1. The replies here said yes, go with back surrounds. So I did make the change. No discernible difference, to my untrained ears at least. While doing this I also replaced virtually all the crappy speakers wires with pure copper wire purchased from Monoprice (thanks again youthman) and wired in a set of old, unused dusty PBS bookshelf speakers for the rear. I had to set the Onkyo software for old back speakers to a +4dB to match the other spekers. These old speakers are temporary until my newly purchased set of Klipsch RB-51 II,s arrive.
To hear the sound quality and dynamics of a contemporary movie I put on the latest streamed Avengers, assuming it would have all the various sound bells and whistles. The sound imaging was fantastic. I cranked it up and actually had it at 0dB for a very short while. I use a velodyne 12" sub and didn't hear any distortion. Crashing, explosions, choppers, everything was right where it was supposed to be. I am very pleased with the results. I'll try a blu ray Batman video later today. I'll try to hear if there is a difference in dynamics and clarity between streaming and DVD.
My next addition is putting a set of Aura Pro Bass Shakers under the couch to add to the realism of a movie. Got to do this while nobody is home because I have to modify the underside of the new couch. I am going to video the wife's expression when I put on Jurassic Park. As a side note, I am going to do the "subwoofer crawl" today. She is going to think I have gone over the edge.........later.