I just bought a mint condition Thiel CS.5 and very happy with the results I am getting in my room. This is a serious speaker indeed. Paired with a Vincent SV-236MK integrated amp (tested also with a Rogue Sphinx and a NAD C275BEE power amp) it produced a big holographic sound with amazing consistency from top to bottom, and for my surprise they were the most easy speakers to place in the room up until now.
The speakers just disappear and the bass is very satisfying in my 3,6 x 4,9m dedicated listening room. Some CS.5 users reported a week bass output but in my room (and to my tastes) it is are very good and proportional to the rest of the spectrum.
A praise must be given also to the top end quality: I am discovering so much new details in very well known records... it is addictive!
Some of my other speakers are: Totem Arro, KEF LS50 and Duevel Planets, and they all have their strengths but I find the Thiel to be easily more engaging and true to the music.
I also love the design and the built quality and I am proud to own them.