The McCormack and the Bryston are both terrific amps, and the EC product line has always had a fine reputation. The Bryston has, by far, the best warranty (if that's a buying consideration). Of these amps, I'd go with either the McCormack or the Bryston, but you should audition both with your speakers -- preferably in your home, with the rest of your system -- before you make a purchase. Both will do a fine job of driving your Thiels, but they do have slightly different sonic characteristics. The Bryston 14B-SST may be the most "chameleon-like" in its qualities, perhaps because it is very neutral, allowing the other components in your system to exhibit more of their own "character".
I have heard both the Bryston and the McCormack amps you are considering, and I could live very happily with either one.
I have heard both the Bryston and the McCormack amps you are considering, and I could live very happily with either one.