Hi Tom - I own Thiel 3.6 and have for around 17 years and CS 6 for about 4 years. I switch them in and out every few months or so, right now using the CS 6.
The only amplification I have used are Mcintosh 501 mono’s and Classe CA200, both of which I am intimately familiar with since I have owned both for several years.
Both are interesting, the 501’s have an obvious control over both speakers. The Classe’s also have plenty of control, great midrange textures and are more open than the darker sounding Mac’s. The Mac's might have a small degree of refinement compared to the Classe, perhaps the addition current. Neither amp ever gives the impression of being “taxed” no matter how hard they are driven. And I have been know to drive them with some good classic rock, blues, and jazz.
My room is large, 18 X 40 and I get plenty of Satisfying SPL with both amps. I also switch them in and out every so often.