I would recommend the Harman Karkon AVR-247 and Yamaha RX-V661 over those two. My personal favorite in the $400-500 range is the Harman Kardon AVR-247.
I can personally vouch for the Harman Kardon AVR-247.
After owning that great product for 3 months (sold it to my little brother because he needed it more), I have a tremendous respect for all Harman Kardon products!
If I were to sell ALL my separate components, I would have to just wait for HK to come out with a new top-of-the-line receiver that has HDMI 1.3/DTS-MA/TrueHD.
Example, when HK says that it is rated at 50 wpc x 7, it actually measures like 80 wpc w/ all 7 ch driven, or 100 wpc w/ 2 ch driven.
When other companies say it is rated at 100 wpc x 7, it actually measures like 50 wpc w/ all 7 ch driven, or 80 wpc w/ 2 ch driven.
But that's just one little part of the story.
I've compared the HK247's direct stereo vs my RL-11's true analog stereo, and the HK247 came extremely close to being as good as the RL-11 preamp.
Another plus for the HK is that it is the least expensive AVR to use Faroudja Video Processing for 720p upscaling.
Keep in mind that HK is owned by Harman International, which also makes Mark Levinson, Revel, and Lexicon!