I am, in no way, affiliated with GR research....just my personal experience noted.
I have purchased and built two sets (4 enclosures) of the AV-1RS from GR research for the surrounds on my 7.1 setup. When I was considering purchasing these to complete my setup, I asked Danny at GR how well they would work/blend with my two front channels and center channel. They are two Klipsch RF-83s and one RC-64 center channel. When I told him about owning these, he said he would honestly look for better speakers than my Klipsches to mate with his surrounds. At the time, I thought that this guy was just proud of his "babies" and probably thought a little too highly of them. I WAS WRONG.
In order to quickly test the enclosures after building, I simply disconnected my Klipsch center channel and plugged each enclosure in to make sure all the connections were good. I was blown away. These shoebox-sized units destroyed my expensive Klipsch center channel in respect to sound quality, both in range and clarity. There was no comparison. The Klipsch should've been a little louder because of sensitivities, but I did not notice it if it was.
I am just writing this to encourage anyone who is considering this company, to give them a shot. I wish I had prior to purchasing the expensive Klipsch fronts and center. I could've saved a bundle, had a unique setup, and outperformed what I have now by a mile.