Okay, I've tested the system out and listened for several hours. I also hooked up the VP180 once I unbridged the amps. Here are my opinions.
Sound Quality - At least as good as the AVR-3806, and I think a good bit better. My wife thinks it's much, much better. Sound seems tighter and less muffled. I don't know if it's a characteristic of the Class D type amplification, having separate amplification, or a little of both. We switched back and forth between the AVR-3806 and the ClassD amp several times, and every time it felt like cotton came out of our ears.
Power - Here's the rub. I cannot test the unit to full power, even in unbridged mode, because the amps will cut due to high temperature. The best I was able to sustain without any cutouts was a constant 102db in my listening position. When I looked at the wattmeter, I was pulling about 90W. That's with 3 channels going too. Interestingly, the VP180 always cuts before the M80s. Maybe something changed with the new crossovers and drivers. The website (and the people on the board) have said that higher power demands require an active cooling system. When I shot the heatsink, it was at 73C constant. So, I think adding fins on the heatsink and the addition of a fan would allow me to bump the power up.
Fun Factor and Ease of Build - It's REALLY easy to build and a lot of fun. I'm really proud of it even in it's unfinished state. Knowing I can go in and tweak things (like thinking of a way to provide a more robust cooling solution) is a lot of fun for me.
Recommendation - I would recommend these kits for people who normally listen to music below 100db. If you listen in the 85-90db range, there is no problem whatsoever, and you can go with a much smaller toroid and amp size (driving the cost down even more). The sound quality, at least to our ears, easily rivals or beats that of high end professional equipment. I would also recommend this kit for someone looking to amplify surround speakers on the cheap, or someone who likes to tinker around (especially coming up with a nice cooling solution).
I'm going to keep the amp hooked into my system. I like the change in sound that much. Plus, I usually listen in the 90-95db range, so I'm good with the volume. I just want to be able to figure out a good way to get the most I can out of the amp modules... But hey, that's part of the fun right?
