"In my opinion, many of the long-standing and ubiquitous criticisms of Thiel speakers as 'bright, in your face, aggressive', etc. are due to amplifier distress."
I couldn't agree more. I've owned 2.3s, 7.2s and now 3.7s. In addition, when a friend worked at a high end shop, for about a 6 year period, I did virtually every install and set-up with him, including Thiels (and other brands). Thiel models included, 1.6s, 1.7s, 2.3s, 2.4s, 6s and 7.2s which I was involved with multiple times.
On my first trip to the store, I was temporarily renting (had relocated to the area) waiting for a house to be built and I ended up buying a Rega Planet CD player for my temporary set-up in the rented townhouse. They had a pair of 3.6s in the showroom but I never got to hear them. Between work, work travel and staying on top of the contstuction by the time I got back to the showroom the 3.6s were gone. I didn't start going out on installs/set-ups until after I closed on the house several months later and got settled in.
I've heard good and bad set-ups with Thiels. Mostly good as when people came in to buy a whole system, they generally played something appropriate for the speakers. There were those who just bought speakers and sometimes what they had didn't sound very good to me.