dsper, this doesn't address your Tekton/Klipsch question, but may relate to the Thiels.
In my experience charles1dad is absolutely correct, "So most likely complex crossovers probably siphon off more amplifier power."
For years I owned a pair of Duntech speakers. They were rated at 90 dB, but had very complex first order crossovers designed to maintain time and phase coherency. That would be similar to your Thiels. Dunlavy recommended at least 100 wpc, with 200 "for musical enjoyment". Over the years I tried a wide variety of amp types and power ratings. I finally settled on Parasound JC-1 monos, rated at 800 wpc into the Duntech 4 ohm load. They taught me about complex crossovers.