D'Agostino vs. Ayre

@gdnrbob The Atma-Spheres were Excellent, especially in the mids and highs. I think they just could not deliver enough current for the sub-2ohm load of my Alexia's in the bass. 

The D'Agostino S-250 is equally excellent, but across the whole frequency spectrum. I Love It. If you can score a used or demo S-200, the cost to upgrade to an S-250, I believe, is $7500. And there is No Comparison between the original D'Agostino M-300 or S-200 vs. the new M-400 or S-250. I'm looking forward to hearing a VTL S-400 II in my system, maybe someday. Will it be better than the D'Agostino?? I don't know.

I heard the Alexia 2s at RMAF. Amazing loudspeakers. Driven by all Nagra electronics, they were truly magical. And that's under show conditions. I understand Wilson has redesigned the crossover in the Alexia 2s to make them more amp friendly in the bass.

@OP,
The Zero Autoformers would have compensated for the low impedance of the speakers. I know Ralph recommends them for older Maggie's which have the same characteristics.
Though my Vandy Treo's are fairly easy to drive, I bought a pair of Zero's to try. Steve McCormack says they do make a difference, too. So, I want to give it a try-just for fun. If a SS and Tube guy can agree on something, maybe it has some credence.

B

@gdnrbob.  
I find it interesting, in theory, that a designer like Ralph Karsten specifically omits the output transformer in his designs (hence the OTL) to eliminate the distortion caused by the induction in an output transformer. Then someone, like Zero Autoformers, creates a transformer in a box to be added to the signal chain to alter the impedance. But the only thing that matters is the sound. Please let us know what you hear if you try some.

gdnr

RV said this about the autoformers in my Mac 202...

move on and never look back

he may actually have been more direct
it has been like 7 years....