In my opinion, the Bryston will make you never look back at the Adcom. I have had Adcom amps for 40 years, converting most of the generations of the amp line. When I switched it was night and day. Definitely not shrill in the upper end, or sterile. The low end absolutely came alive with so much more depth and emphasis.
i am currently running Bryston 7BSST Monoblocks from an Adcom preamp (which will be upgraded soon) into B&W Matrix 801s3.