When people upgrade from Thiel

A lot of users "move" away from Theil due to the fact that they no longer want to be restricted to using a large high current / high output amplifier. 

Also, you need to distinguish between pre or post Jim Thiel speakers.  IMHO, a lot of people upgrade away from post Jim Theil speakers because they can achieve better performance for much less money.

It may not be an obvious step, so what more are you craving? I still own my Thiel CS 3.6 speakers, but my musical tastes shifted as I got older seeking out a more relaxed sound. Now, I have 300b amps and Horning Speakers, so I kind of flipped 180.

What's funny, is just before I clicked on your post, I was thinking, what good value solid state amps could I pair with my Thiels as a second system? You see, I love my new setup for the jazz and such, but sometimes I miss cranking it up for rock n' roll with the Thiels.
Kenny

I recently went from Thiel CS7 to Marten Django XL. I tried for the longest time to find the uograde kit to take my CS7 to CS 7.2 but no luck. The Martens offer the next level up (from the CS7) in terms of air, open, accurate mids and bottomless bass. At least in my system. (NAS, Auralic Altair, Parasound Halo JC2-BP, Bel Canto ref 1000m)

Owned Thiel 3.5s for 8yrs. Kept blowing midrange and tweeters. When Kathy Gornick said no more drivers would be replaced under warranty. I sold them. Took 4yrs of Sonus Farber, Wilson, ProAc to finally settle on Avalons 

I owned the CS6 for about 10 years and when I decided I wanted a different sound, I bought the Harbeth M40.1.  I've had my 40.1 speakers for over 4 years and I have no desire to change.