My personal preference in OTL sound, from commercially available amps, was the big Joule OTL (warmer sound than the Atmasphere or Berning), but, the model I heard had problems with tube sockets going bad which caused it to intermittently put out a HUGE pop; a friend with 105 db/w speakers said the pop was as loud as discharging a shotgun indoors. I heard that pop on far less efficient speakers and almost had a heart attack.
I did not understand the appeal of the Tenor at all. In the systems I heard the Tenor in, it did not deliver the incredible dynamics and liveliness that is the primary reason one goes for OTLs.
I also liked the sound of the SAP OTL, but, that amp too, turned out to be unreliable.
The only practical alternatives out there that I know of are Atmasphere and Berning models. Both are certainly worth an audition. I am a tube fan, but, I don't like most high powered tube amps. If I had speakers that demanded more than 40 watts, I would certainly be looking into OTL amps.