Regarding your question about surround speakers- I have only heard the 2-channel Thiel loudspeakers (2.4, 2.4SE, 2.7 and 3.7).
None of those dealers/retailers had any in/on nor sat Thiel speakers.
All auditions were in a 2-channel listening room or showroom.
Hopefully, one of the other guys here can be of help to you.
Happy Listening!