Vintage Krell Amp... Which would you choose?

Dsper, with most any other speaker, the 200S would be plenty enough. With your Thiel CS5's with all those drivers, huge cross-over and most demanding load, it's good enough,  but if budget permits, those demanding speakers could benefit with even more power. It's not loudness so much as stress free ease. Remember, doubling the power is just a nudge of extra volume.

Dsper:  I admit to not being a fan of the "S" series of Krell amps, which were the first to use the sustained plateau biasing technology.  I feel the earlier KSA 250 was far better sounding than any of the S series, and that the FPB series were also far better.  And FWIW, I don't think the 200s would be able to get the best out of Thiel CS5s--a KSA 250, MDA 300 or FPB 400 would be better able to handle the low impedances in the Thiels.

Krell FPB 300cx. Sweet, powerful, durable and reliable. What else could you want? Mine is 14 years old and going strong, never even a hiccup.

Neal

Hey RCPrince, There is also a recapped 300S for sale out of NY - think that may be enough oomph?

That might be enough, but I still prefer models other than the "S" series.  They might have been more neutral than the KSA250/MDA 300 amps, but to me they sounded almost sterile, lifeless in comparison.  Guess I'm a fan of distortion.