The JCM 800 is also my base preset. I have kept the Amp and cab, but tweaked it for how I play, including a USA Clean and different cab for it on scene 3, and some other variations.
I also use both U2 presets, Limelight, Plexi+B3 (my band plays the Chickenfoot version of Highway Star), and several others. I also modified my base JCM 800 and put it on another preset with the amp swapped out for a rectifier amp for those kinds of tones for a few songs (which my drummer says is his favorite sound).
I could do a whole night with my main JCM800 preset, but I think I use about 16 presets, 3 general purpose, and the rest song specific, for a night of 40 songs or so, because with the Fractal, I can! And I even talked the band into playing a few songs because Moke made some killer presets (like the 2 U2 ones), and that really stretches our song list to be more interesting than some of the other local bands in the area.
My band just has one guitar, bass and drums, with a vocalist (and the bassist and I sing as well), so our sound man loves the tone changes to mix things up, and we get some very nice compliments from the audience as to our versatility!