Thiel Owners

Michaeljbrown...

I can heartily recommend Pass Labs X150.5 or up. I've seen a few in your price range and to my ears were the best amps for my CS3.5's. 
The X150.5 is 150 watts X 2 into 8ohms, 300 into 4ohms. I had an ARC LSB2 for the preamp. 

Also, I can recommend looking into a Pass via Reno Hifi here. I have no affiliation or mercenary connection to Reno but my two quick transactions with Mark were exemplary.  I purchased a First Watt M2 from him and almost immediately stepped up to the 150.5.  Full credit for the M2 towards the 150.5. Pass ain't cheap at any level so knowing you're dealing with a class act is reassuring. 

Have fun in your quest.  Thiels reveal!

oblgny, The spikes for the 3.5's are intended to couple the speakers to the floor where appropriate(!). These early Thiels were provided with two sets of spikes, one set was blunt tipped for direct contact with hard, firm flooring and the other set was pointed in order to pierce through carpeting to make contact with firm flooring. The spikes when inserted into the speaker bases hardly protruded, and not intended to be used just to elevate the speakers. In fact, Thiel suggested not using them when the speakers would be placed on flooring that might vibrate with such coupling. Thiel used to offer the replacement spikes for a very nominal fee.   

The Thiel CS 6's are less sensitive, the minimum impedance nearly half that of the Theil 3.5's, and the Thiel recommended more power for the CS 6's (100-400 Watts per channel) than the CS 3.5's (50-250 Watts per channel).

UNSOUND - I have always been curious about these power ratings. Are they taking into account impedance at the higher rating? For instance with the CS 6 is the higher rating due to lower impedance swing?

I've always assumed the recommended power was based on an 8 ohm load since that's how amps are normally advertised. It was up to you and your dealer to recognize that you needed one that doubled down at 4 and 2 ohm.