Check out the AV7005 thread:
Looks like the AVR-3313CI, which I'm sure is very good, is 7.2 (dual sub's), and uses Audyssey's MultEQ XT EQ system. Also is 4K compatible and more. AV7005 is 7.1 processing, uses Audyssey's MultEQ XT EQ system as well, and is not 4K compatible.
However many seem to prefer having Audyssey's MultEQ XT32.
I have AV7005, still waiting to set-up. But may consider upgrading to AV7701 before permanently installing AV7005.
Don't know anything about the Sherwood [performance] myself. But I think you'll be happy with the AV7005 in comparison to the B&K 307.