I'm in a similar position. I like to purchase high end equipment used when the prices drop. I currently own an AVR305 and absolutely love it. When I first bought it used four years ago, the sound began dropping out periodically. All five channels would drop out for a second then come back. I too called B&K and they said to mail it to them for diagnosis. I felt the unit was good enough to invest a little more into it. A couple of weeks later, I called B&K and they told me that my problem was very minor and they fixed it for free. They knew I wasn't the original owner, but still fixed it and shipped it back to me at absolutely no charge. WOW!!!
I recently got the bug to look at new receivers with HDMI. I don't have it in my budget to get an AVR707 (by the way, why is the 707 only 125W? This seems like a step backwards). It didn't take me long to realize, that buying a new, non-B&K with HDMI, would be taking a large step backwards in sound quality. I'd rather just feed my audio to the receiver and have a seperate HDMI switch for my projector. I've decided I'll probably be a life time owner of B&K for now on.
I'll be building a new home in about a year, and I'm planning on a larger dedicated home theater. It will probably be around 18 X 25. I feel that this size of room could use 7.1. I'm thinking of selling my AVR305 an buying a used AVR507 or an AVR507 Series 2. My reasoning is the 507 is a little newer and the processing should be better. I believe the Series 2 is even newer. I realize I can buy a seperate amp for my 305 and make it a 7.1 system.
Here are my questions.
Are there any opinions on the AVR305/7 versus the AVR505/7? Is the processing better with the 505/7. Any opinions on the series 2 (is it newer and better)? If I can get a better deal on a 505, I can always add a stereo amp to power the rear surrounds. With the very little information that goes on back there, is there any opinion on using a cheaper amp to drive those channels (keep in mind my tight budget)? I realize a cheaper amp will not sound as good, but do I really need an expensive amp to hear a bird chirp or some crowd noise from time to time? It seems not many movies are even recorded in 7.1.