I thought it was a good pairing. It provided a dynamic setup with nice detail and bass response. I also heard the speakers through the ATC integrated. I thought they were very similar with the Cary having a slightly richer lower midrange, and the ATC more inner-detail.
As you know probably know, the speakers are very detail and neutral with a phenominal midrange. If you go with an amp that has a brittle upper-end (such as an older, krell kav series)it may provide a fatiguing experience. I wouldn't blame the speaker. ATC's should never come across as fatiguing unless its the amp or actual music selection.
Just my opinion.