What is the best OTL out there?

Mactone OTL monos.

Thanks for all your inputs! I see a clear convergence on Atma-sphere, and I will definitely look into it. A friend of mine has their MP1 preamp and raves about it. I suspect that something like the combination MP1 and their M60 amplifier might be very interesting. I have a pair of stacked quads to drive, and I don't need more than 50WPC.

I personally think Berning is a genius based on what I listened to (as I said I had a Siegfried and also some of his earlier non-OTL amps), but I wonder if he is overpriced relative to the competition.

A friend of mine (a famous musician and serious audiophile) swears his favorite amp ever is a Tenor. Never had a chance to look into it. On the negative side, he also said it had some reliability issue.

Atma-sphere is certainly good, if is it the best, I don't know. In my case, OTL amps bettered heavy-duty solid state amplification. I had a flagship chain - Krell FPB600 driving Dynaudio Consequence speakers. I bought Atma-Sphere MA-1 and got them factory upgraded to mk 3.2, and to my ears, this sounds better. But it happened only when I changed from 8 ohm speakers, to 12 ohm (Audiokinesis). You get the diamond edge of OTL amps only through high-ohm speakers. If not, it may sound ok, but it is not optimal.

At the Newport show a few days ago I had a chance to hear OTL monoblocks from both Einstein and D Berning. OTL's are definitely closest in sound to no amp. Both were pure and endlessly open on top and both had tremendous presence and authority. Both were 70- 80 watts as I recall. In my judgement the system with the Berning amps sounded somewhat clinical and less than natural on top when pushed. The wide open bandwidth of an OTL can also invite unwanted super sonic spurious crap that gets into the picture... if not properly addressed.
The Einstein OTL mono's were my preference...(that day). Big, insanely open, realistic, clear and alive... and totally non-fatiguing. For the record, the one non-OTL amp that sounds closest to no amp is the Technical Brain amps from Japan just beginning new dist. in the U.S.

Cheers

"The wide open bandwidth of an OTL can also invite unwanted super sonic spurious crap that gets into the picture... if not properly addressed."

It's ultimately an issue I hear as well. The level of transparency offered by an OTL mandates that EVERYTHING be balanced less hearing a bit more than you bargained for, that balance between clinical and musical which might be heard as an initial WOW as the brain starts working to fill in the blanks vs. being relaxed and engaged in the music, not the sound. When they are right, dialed in with the right components and addressing room issues, they can be quite special in their presentation.