I've been considering assebling a system dedicated to choral music like you describe, which seems the most difficult music for my system to play--Beethoven's "Missa Solemnis," Desprez's 20-voice "Qui habitat," Tallis's "Spem in alium," and the like.
I have a Cary SLI-80 with Svetlana KT88s and lots of preamp tubes, a Cary 303/300, and Sonus Faber Grand Piano Home speakers (90dB/6ohm nominal). This is an excellent system for most all other music--symphonic orchestral, opera, chamber, jazz, etc. But large choirs with massed dynamic treble voices can sound very harsh--treble glass, distortion, etc.
Does your SET system reproduce these choirs well? I've been thinking about assembling a SET system based on a PX-25 amp and some kind of single-driver speaker, either C&C or Zu.
Thoughts?