I was glad to find this post as I have an Onkyo TX-NR900, which specs out (110w)about the same as the 3802. I run Polk RTi12's as my mains and was thinking of doing exactly the same thing with a couple of M-Blocks.

I was mainly trying to decide if it was worth the money to "waste" 2 channels from my receiver. From what you guys are saying even though I am only doubling the output I should notice a big differnce with mono-block amps when compared to receiver amps.