I have 2ea 3/4 back Mesa 1x12" with EVM 12Ls in them. I also have a Thiele w/EV. I have various 2x12s and 4x12s with Celestion, Weber and Eminence speakers from G12k-85s, G12K-100s, MC90s, Vintage 30s, MS150, Michigans, etc. They all have great sounds with this amp.
But, if I want a smooth, creamy, ripping lead tone, the inefficiencies of the Scumback makes the amp work a little hard, giving it a Greenback meets G12-65 kind of tone that records VERY well. It is a closed back, Avatar contemporary.
These speakers are expensive and I usually play out with a Celestion or EV, but the Scumback sounds Stellar, IMHO.
I do agree, we all have different tastes. When I researched this before the purchase, there were not any searches that returned Scumback/Mesa so I wanted to get one out there.