Thanks for putting this together, Steve! I started doing that exact same thing when I was putting together my review for the Denon AVR-E400 to post here...but I clearly never finished it.
One suggestion that I'd make is to look more at street prices from authorized dealers rather than MSRP. For example, the Onkyo TX-NR626 has been $500 on Amazon for over a month, and it's a stronger competitor than the 525. I've seen the Denon AVR-E400 as low at $350, and the Pioneer VSX-1123 as low as $430.
Regarding the Marantz NR-1504, it's form factor really is quite cool, and it's really a nice looking unit. 5.1 is plenty for a lot of people (unfortunately, not for me), it has a detachable power cord, and it has the pre-amp outputs for the front speakers...although I'm guessing that most folks who buy it for the small form factor don't want to add a bulky amp to it. While it has a lower rated power, it weighs very similarly to the others - that thing is dense. The remote, though, sucks in my opinion because it's not universal or learning (like the Denons).