I am enjoying my analog system, but what can I do to improve?

As Lewm mentioned, the Quad 57’s are a small electrostatic speaker that might work but it doesn’t provide a lot of low end.
Also, those jokes about electrostatic speakers being for audiophile masochists…. I just had my amp tech over today to clean my output relays and found that my right Quad was arcing and making a popping noises. So back to my speaker tech to replace a panel or two.

Synergistic Research has a new and expensive record mat. Anybody used or heard one of these compared to a Herbies or Funk Firm?

I apparently do not understand the term 'dynamics' where it pertains to speakers if Quad ESL's lack dynamics. To me, the term dynamics means whether the music is played from ppp pianissimo to a triple forte. If I were to listen to Andras Schiff play a Beethoven Sonata and if I had the piano score to follow along, the dynamics through my Quad 2905's would be right on. So I would vote for the Quad 57's given their richness and life like sound but yes, they do lack where it pertains to the lower frequencies. And, I wouldn't advocate timing up a sub woofer with the 57's unless it was modified by somebody who really knows how to make it sound cohesive. This would typically mean incorporateng lower frequency mylar panels.