Bryston 4b SST or ARC 150.2 on Thiel cs2.4

Currently my setup consists of an ARC LS2, Bryston 4bSST on Thiel CS2.4, with Kimber Hero and 4TC cable. I find the setup a bit too bright. I think it's the combination of the Bryston with the Thiels. Can anyone confirm that?

I am wondering if the ARC 150.2 would give a better result. I can buy one for a nice price.

Any comments?