Does anyone out there own a Supratek Malbec or Mondeuse amp?

Slowhand - 
I apologize in advance. I can't answer your question about any of the Supratek power amps. But I do have a few comments about your Sanders Magtech, if you'll bear with me.
I have not owned any of the Supratek power amps. And, given Mick's keen ear and vast experience I'm sure that they would sound every bit as good as his wonderful preamps. 
But, I also own a Supratek Cortese and, until last year, owned the predecessor to your very fine Sandersound Magtech. Mine was an Innersound Electrostatic amp. 
Roger Sanders is a talented engineer, designer and builder. I found the Innersound Electrostatic amp to be absolutely brilliant and would still own it, except the protection circuit Quad puts into their ESL 63 family of speakers was death to that power amp. As you well know, Sanders designs his amps with those enormous reserves of current, so they perform beautifully into very demanding loads. Imagine what happens when you "crowbar" the speaker and the amplifier essentially dumps all its power into a dead short. Right - it damages the circuitry inside the power amp.
The current-dumping amps built by Quad are similar in design to the Sanders/Coda Technologies amplifiers but are designed to withstand the ESL protection circuit, so that's what I'm using now.
I plan to keep an eye on this thread to see if anyone can speak to your original question. In the meantime I can't help but think your current electronics perform pretty close to state of the art. I love my Supratek and am a big fan of Roger Sanders work. And it represents tremendous value for the level of performance it provides.

Thanks very much for your comments. I am very happy with my setup, but I always wonder what a full Supratek preamp power amp setup would sound like. 

I will be getting my Cabernet within the next couple of weeks. I'm looking forward to hearing what it can do in my system. I noticed a 6l6 based set of mono blocks he highlighted in his blog. It is essentially exactly what I am looking for. While I have spent my budget for this year (and possibly even next year), I asked about the possibility of making a set for me. Mick told me that he has been flat out doing preamps and hadn't done any power amps in quite some time. He thought that he could possibly do some next year but he didn't sound convinced that he'd be able to. I would love love love a set of these http://supratekaudio.blogspot.com/2019/07/supratek-power-amp.html

So alas, I have not heard any amps from Mick myself but I hope to be able to order some in the future. 

I am in the same boat, but it doesn’t look likely that he will make any power amps in near future.
Too busy with all the pre amp orders to finish. 

@isaacc7, 
Thanks for posting that link. Very elegant and attractive amplifiers and the choice of wood chassis is particularly beautiful. Zero feedback design push-pull as well. If they sound as good as they look (And I suspect that they do) 4,000.00 USD seems exceptionally reasonable.

This represents the downside of a talented person running a one man operation. You become so busy due to demand for your products that one can become overwhelmed (Or nearly so) filling orders. He just doesn’t have the time to produce those gorgeous mono block amplifiers.
Charles