I've got a GM2 that i've run through the serial loop of a Diezel D Moll and an Engl SE. In my experience it's been pretty transparent and is not a tone sucker.
Make sure you set the Kill Dry properly. Believe it needs to be off for serial loops.
No talent and no drive. I went to high school with the drummer for Sympony X and used to jam with him from time to time. Learned what real talent was then. So even if I didn't have it I got a whole hell of a lot of free concerts with some excellent musicians. Found that I'm a better fan than...
Fuses arrived yesterday and i was able to check it out today. I've pulled the tubes and powered up with no issue. I then replaced the tubes and fired up, also no issue. So at present all good.
I haven't connected the effects loop and midi back up and that will be the next test.
I've been having some issues with the D Moll of late. It started yesterday with the amp not firing up when I hit the power switch. I replaced the fuses in the Main and that brought it back to life and it was fine all day. Today however when inspiration hit and I hit the power it was out again...
Never played the Einstein but based on your tastes I think you'll really like the D Moll. As Peter said, you get the best of both worlds (tight and fluid) with channels 2 and 3. Take that plus a super clean channel and midi control and it's a hands down win.
I played around with the base settings on the head but couldn't get it exactly where i wanted. An mxr 10 band in front with a base cut was the key. I have a beastly tone that makes mama proud.
One of these days I'll try out a diezel cab and see how that works out but until them I'm one...
The cab is rear loaded I believe. Handles bass very well and is overall a great sounding cab. I'm playing at bedroom levels so maybe that's part of it.