A question for fans of Threshold amplifiers

I'm very lucky to be able to hear numerous highly regarded solid state amplifiers in my home because I do professional reviewing.  In the last year I have been able to acquire three pristine re-capped E-series Threshold amplifiers.  These are a S/350e, S/550e, and a SA/4e.  When compared to some of the most highly regarded/high price amplifiers on today's market, not only did they hold there own, but particularly the S/550e/SA/4e, I found to be superior in my system.

It has been a long time since any threads have discussed any Threshold amplifiers at all.  So, I'm curious if there are any GON members who use any of the Threshold E-series amps and what your experience has been at comparing them to current production amplifiers.