Upgrades for Thiel CS 3.6?

Upgrades pending.

MikeyBc33 - I think you might well be right... I know there are some “known” upgrades for the CS  2.4 and was wondering if something similar was available for the 3.6. 

@masi61 - I have an Anthem Pre2L Preamp and an Anthem Amp2 Power amp. This is a nice match, but I am certain, for a tremendous amount of money, I could probably do better. 
That’s the problem - a first world problem - I am very happy with what I have. It’s very good. But to get a notch better, I have to spend a fortune. 

@soix Thanks! I am a long-time Thiel fan. I fell in love with the CS 1.5 when I was in college, during the early 1990s. I bought a pair brand new and still have them!

The 1.6 was a big improvement on the 1.5 and, as you mentioned, the tweeter is a big part of that difference. Plus - what a beautiful cabinet design. 
If I could soften the tweet on the 3.6, I would. I don’t mean that I would make it quieter, but just a bit less bright. This brightness isn’t always apparent, but if a recording has a lot of high frequency noise, like some rock recordings do, it gets really bright in a hurry. 
But then, to listen to Muse’s Absolution CD is a delight. It’s very particular to the recording.

@masi61 - Forgot to mention, gigantic brass spikes. They sit on 100 year old oak floors.