Help me find WARM speakers a la Sonus Faber

Used original Cremona can be had for less than half that price. I like them better than the Cremona M that replaced them. The original Cremona are fuller and lusher to my ears. Some think them colored and like the M better. They match well with McIntosh equipment, although I have not heard the Cremona with your equipment. Just be sure the speakers can be traced to an original sale from an authorized US dealer as Sumiko can be a problem if repairs are every needed and you cannot prove they were purchased from an authorized US dealer. Used Cremona M are readily available here and Cremona do come up from time to time.

What is a room dimension?

Marten Django XL (used)

Sonus Faber Eclipse/Eclipse SE (used)

Good luck in your search.

A local dealer recommended Vienna Acoustics Beethoven Grand

Assuming this is the Concert Grand, it appears the dealer was not considering your MC275. If you look at measurements in the Stereophile Review, it indicates the speaker is not suited for a tube amp, even suggesting a result of increased treble, which would seem to work against what you are looking for. Also, measured sensitivity was nearly 4db lower than specified. This also makes me question this comment,

If he cannot and is truly being a good guy by recommending a speaker that you would have to buy from a competitor dealer, then I applaud him and would take his advice. He has given you a good suggestion.

So, are you just looking for this dream speaker, and if it doesn't work well with the MC275, you're fine to replace it with a solid state amp?

or

Are you looking for a dream speaker to use with the MC275?

The 2nd will definitely have a more limited selection. IMHO, if you want to use the MC275, I would make sure the speaker is tube amp friendly before spending 10 grand on one.

Sonus Faber speakers are warm, beautiful sounding speakers. My advice would be not to settle for an imitation. Sonus Faber has been making speakers for decades. People who buy them take care of them. Get a used pair! You'll never regret it. For ten grand you could find a pair of Extremas or even the original Electa Amators (for much less) and you will always tell yourself how smart you were to follow this advice.