Heard Bel Canto Evolution II driving B&W 803 several times at a friend of mine in Virginia. Very very delicious, resolving, musical, fast, and authoritative! I suspect that the newer Ref 1000 monoblock would work even better. I have used R1000 Mk.2 and reviewed them in the Mk.2 version on my Vienna Mahlers that are even more difficult to drive than 803s. . . and they drive the creatures with aplomb. My review is at:
http://www.positive-feedback.com/Issue43/bel_canto_ref1000.htm
http://www.positive-feedback.com/Issue43/bel_canto_ref1000.htm