michaeljbrown...
It may well be that a lot more of the CS3.6's were sold than your 6's, but could it also be that people are way more reluctant to give them up? The only reason I sold off my 3.5's was to offset/fund the purchase of my 3.6's which, as you can imagine, was one of my better audio moves on the last few years. The fellow member who purchased the 3.5's from me drove from Massachusetts to pick them up - and these were to be his second, perhaps even backup pair lest his current 3.5's need repair. Thiel folks are a stubborn lot, ain't we though?
My Audiogon/Thiel addiction has had me checking out Thiels for sale virtually every day for the past couple of years. There's still a pair of 5's up for sale that have been there for well over a year, a pair of Cs5i's came and went on eBay, then came and went again with no sale - at least to my knowledge. With the legacy models being extraordinary bargains unlike any other brand, I'm quite surprised that a secondary market hasn't proliferated. There has yet to be a single person who has heard my system that isn't impressed as hell with the Thiels.
For now I am happy as a clam with the 3.6's, and they, like your 6's, may find a mention in my will...I'll be cremated, but not the speakers!