Red Rose Levinson M-1 Reference Monos

Do any of you have experience and onions to share with Red Rose Levinson M-1 Reference Monos. There is an ad for these on Gon today. I always thought these amps are beautiful, but do they sound great?
I have a pair of these amps which I use to drive the ribbons of my Wisdom Audio M75 speakers (I use a Rowland 8ti/hc to drive the bass units).
These amps are essentially Audio Prism "Manna" amps (except that the case is now silver instead of the original champagne). Mine are from Audio Prism but I have had them upgraded with the several improvements that the most recent M-1s included.
I have replaced the stock tubes in my M1s with RCA "black plate" tubes which I think improves the sound slightly, but they sound great with the stock tubes too.

At the price that the used pair is being offered, I don't know of a better amp. At their list price of $25K, you might be able to find amps that sound slightly better if they are compatible with your speakers.

The Mannas (M-1s) are capable of driving fairly difficult loads. For example, the Wisdom ribbon dipoles have very low impedance at some frequencies and many tube amps do not work well with them, but the M-1s handle them fine.

I have recently been informed by the manufacturer that there is a new upgrade (improved output transformer) available.
I'm not sure about differences between the old AudioPrism stuff and the new Red Rose/Levinson gear but cosmetics are pretty much the same. Of course prices have skyrocketed since Levinson bought the company.

Having heard the earlier Mana amps and Mantissa Linestage on numerous occasions and being totally unimpressed, I would suggest a serious audition before plunking my money down. Naturally, anyone owning or promoting Red Rose will say it's a different animal and much improved but I'd be skeptical. I'm guessing resale is not that good either.