I'm running a Yorkville XS800H through my 1212L.
I love the sound of it, which I'd describe as sensitive and warm. I really don't have much to compare it with though as this is my first major rig, but all the other cheap stuff I've played through through sounds dead in comparison.
Only issue I have with the Yorkville is the weight, it is almost as much as the cab. With a cab this light it feels like I should have a micro head. Maybe one day, but I wanted the tube preamp.
I am amazed at the volume this rig puts out, I mean I never get to 10 o'clock. The thought of turning it up louder scares me, such a small cab should surely explode I'd think, but I guess it can handle it?