Airtight 300b or Coincident 300b?

I have the chance to buy either one, 2nd hand used for almost the same price.  Any recommendation which one i should go for?  On the one hand, one is a monoblock while the other is a well established brand using high quality tamura transformer..  Any advice is appreciated.

I am using a diy audio note m7 tube amp driving a pair of audio note an-e spe HE speakers.  currently using a pair of yamamoto a08s.  I have used audio note kit 1 300b before so these 2 would be my benchmarks.

i listen to classical music, mostly chamber, operas, symphonies.