@tomthiel, re: your earlier post re: bi- or tri- amping the CS 5's; this would require modifications, 2 to 3 more outlets, 2 to 3 more shelves, 2 to 3 more power cords, 2 to 3 more pairs of interconnects, 2 to 3 more pairs of speaker cables. The extra Benchmark's would still be limited to the Thiel minimum recommended 100 Watts per section.
With all due respect, I really don't put much stock on what a manufacturer claims off the record; let them put the specs in writing or provide third party measurements (interesting that Stereophile excused the Benchmark from full 2 Ohm testing, either in stereo mode single channel, simultaneous dual channel stereo mode, or mono configuration measurements). While I do respect the Benchmark's low distortion specs, and especially the adjustable gain options, their amps don't read as suitable candidates for sub 3 Ohm loads, and are not exactly power houses above 3 Ohms. In that the Thiel's shallow 1st order cross-overs have so much more overlap than other networks, using identical amps for multi-amp use is of even greater importance.
One used Krell FPB 600 costs about the same (actually a bit less) as two used Benchmarks and can provide substantially more power to each and every driver, without compromising frequency linearity into a speaker thirsting for power, and do so maintaining Class A operation the whole while. One Krell seems like a much better match for the CS 5's.
While with appropriate amplification ( the Krell KMA 400's are the best I've heard them with) I think the CS 5i's are on absolute terms the best sounding Thiel's ever made, and amongst the best speakers I've ever heard, including much more expensive alternatives. Without appropriate amplification they can be disappointing.
I found your earlier posts suggesting reshaping the CS 5's baffles in order to simplify the cross-over as a more interesting/promising proposal.
P.S. I started this post some time ago. I've been a bit busy, but I hope to respond to your other inquires in the near future.