@andy2 I assume you mean non Thiels with a concentric driver? I’ve heard the TAD Ref 1; it has a concentric driver with diaphragms of an exotic material that I don’t recall. One of the very best speakers I’ve heard. Just stunning, but you’d hope so at that price!
My very short list of all time favorite speakers includes both time-phase correct and not. I don’t know if that part matters to my ears a ton but I will say that my favorite speakers at real world price points are Thiels and Vandersteens. One important feature, IMO, is that both of these designers use light and rigid materials in the midrange and with diaphragms <5”. This is super important to avoid distortion in the critical midband. It amazes me that some really high dollar speakers use 7” drivers for the midrange. No thanks!