Old Flagship Vs New Mid-Level Receiver

Folks,

I currently have a B&K AVR 507 which, when I bought it, was about as good as you could get. I'm thinking about getting a new receiver to take advantage of hi-res audio formats and, most impoartantly to me, room EQ. I don't have flagship money this time around so my budget is $1000 tops. Has anyone compared my 507 or something like a Denon 5803 to a new mid-level receiver like an Onkyo 818 or anything else with Audyssey XT32? I'm also considering an Anthem MRX 300 to get ARC. Will I get an improvement is sound? So what is better? An old flagship receiver or a new mid-level one?

Thanks in advance for your responses.

On a side note, I really miss the days of high-end brick and morter stores where I could bring the equipment home :(