Mesa Diesel, Powerhouse and Road Ready IIRC have 2x15. I have a Mesa Diesel 1x15 with the EVM15L and I've always loved putting any amp through it and mixing it with other 12 inch EV speakers.
I had the first prototype of what later became this cab. I went to SLM and tested it out, they were coming out with the digital head and I knew one of the engineers...I had a 7 string at the time so he invited me to the plant to demo it. Awhile later he called and ended up giving it to me. Wish I never sold it
As you know I have the 212/115 I made. I'm slowly working my way to converting the garage onto my music space so I have a little more room to spread out. When I do I plan to build a these cabs.
215 with Weber 15" Blue Dogs
415 with Celestion Fullbacks
612 with Weber Black Shucks