I finally got to spend some time AB'ing the LM800 with the Shuttle 9.0.
The results were quite remarkable in a good way. Let start by saying I had both set flat EQ wise and I had to Gain Match the Inputs with the clip indicator for each amp. The Input on the MB was set at 9:00 and the input on the GB was at Input Gain 11:00 and Input Volume 12:00 on the two, this allowed the clip light to come on occasionally when I really hammered the B string on the Stingray with both amps.
Both amps were hooked to one Bergantino HT112ER 8 ohm cab. I set the master on both amps at 12:00 and the tweeter controls on both Berg cabs was set at 9:00. The Bass control on the Stingray was full up and the Treble was 3/4 up (the way I like it).
Oddly enough both amps sounded surprisingly similar. The GB was maybe slightly more woolly and smoother with a slight difference in the midrange between the two amps. The MB has a little more going on around 900 hz (to my ear) and has just a little more clarity. Most of this is to be expected as the GB has a 1955 Mullard in it.
Power and low end wise both amps sounded to me about the same volume and bottom end. I will have to try them cranked a little more and see if they react the same when pushed.
All in all I'm happy with both amps and either will certainly get the job done on about any gig especially with more speaker cone. I could only imagine what one of these would sound like through two 4x10's though I would never need that much.
FGor kicks I did run the DI from the GB into the MB and added 2 more 1x12 cabs just to see what that was like. Kaboom, mamma was not very happy up stairs.