Thiel speaker model range

Cs 3.7s are fab!  If you can find a pair, buy them.

I have a pair of CS 2.4's for sale that are being mentioned here. They are in dark cherry finish. I am the original owner and they are in the original boxes, lightly used. Wife wanted a cleaner room so i put all Thiel Power Points in their place. These were $7500 MSRP

FWIW, both the Thiel 2.7 and the bigger 3.7 work equally well in my 15ft by 13ft room. 

I have never auditioned CS2.7, but I did that for CS3.7 - when my choice was between CS6 and CS3.7.  I think mid-high ranges are
comparable in both speakers, perhaps CS3.7 give wider and more intensive mid-high ranges, although low frequencies are not comparable - CS3.7s  lack them, whereas CS6s give deep solid natural bass. I do not regret that I have chosen CS6s (the coaxes needed reparation that was done in Thiel by Rob Gillum quite well).

I also own CS3.6s and  MCS1s with Thiel smart sub for more than 10 years  already, which I also like. Before MCS1s I had some time CS1.9 that have decent high frequencies but I think their mid ranges are a bit saturated, nothing to say about low frequencies. Bookshelf MSC1s are uncomparable superior to  CS1.9 s.  

I would not hesitate to choose CS6, although if you have a small room and your amp gives  below 100 watts  then perhaps CS3.7 would be a better choice.