<randyhat> I have been using an Audio Research 150.2 amp for a number of years, working with an Audiio Research LS-25 Mk II, Esoteric K-01 player, and driving Focal Alto Utopia speakers. The 150.2 is based on the old Tripath Class D module, but with other elements designed by AR and built to traditional AR build quality.
I play almost 100% classical CD and SACD, and the sound I hear from this setup is excellent to my ears. Specifically, I do not hear the harshness that many mention as coming out of Class D. What I feel that I am hearing is a very clear version of the program material--with all the strengths of well recorded and mastered discs and all the faults of poorly recorded or mastered ones. I have heard the equivalent setup using a Levinson in place of the 150.2 and did not find it significantly better, for my taste.
When Tripath went out of business a while back, AR had to move to their own proprietary Class D technology to make amps like the D225 and D450. I think these are now discontinued with no SS replacement from AR. My theory on this latter development is that the new owners of AR are rationalizing their various brands, with AR becoming all-tube gear and McIntosh handling the SS amps they want to sell.