My amps are the same, with the addition of a second larger 2 channel amp. However, the larger 2 channel amp has pretty much the same design. Exact same gain as the smaller amps... The "sound" is pretty much the same as my M60's, with a much wider field, and more dispersed sound field. This is mainly due to the design of the rear firing speakers and my room configuration.
More enveloping would be the best way to describe it.
As good a description as I can come up with. It's not easy to describe the sound of the LFR's!
So you have one amp for your centre, surrounds, and the rear channels of the LFR, and another for the LFR fronts? What are their output ratings? I was thinking of doing something like this myself but wasn't sure how well it would work.