i sold my yamaha 5930, which looks alot like the 5730, to my brother. he is using it with an epic 60 system, and it is working out for him. I know this doesnt cover the 4 ohm vs 8 ohm situation. also the 5930 doesnt let me set separate distances for the left/right front/surround speakers, so the primary listening area needs to be an equal distance from the left/right speakers.
i think it would work for 6 months, but i wouldnt want to get stuck with it forever. I like my denon 2807 twice as much, but it costs 5 times as much
