I can't agree with that. I had a 6.1 system and disabling the center rear was instantly noticeable and worse. With the center rear on surround information was clearly localized behind the listening position. But the listening position was almost equi-distant between front center and rear center speakers. I suspect a very near rear wall would degrade your experience significantly.

As for the research showing front-rear reversal, OK, whatever. For me, in my setup, with the visual and audible cues in the movies I was watching, it was never an issue. All the speakers were perfectly matched, so maybe that helped.

I'm reasonably sure 7.1 is better, but 6.1, IMO and experience, is worth it over 5.1. For sure.