I've tested:
1) handbuilt, material : mdf(cheap material), 4x12 front-loaded cab, V30 speakers, closed back
2) M/B cab,( I think it's Road Ready), built like a tank, smaller than 1st cab,
bottom: EV12L '85, top: blackshadow c90
and:
3) my friend's Marshall 1960AB with GT-75s.
...
1) heavy, tight bottom, little scooped mids, detailed highs, imho it sounds nice with mark IV, with Marshalls - too harsh (too much treble)
2) no bottom, no highs, just nice mids, too plain sounding, maybe these speakers are too old or something, maybe they're just different(I've heard that EV12L are very transparent etc).
3) not so much bottom like in my V30 loaded cab, but smoother highs. Sounds nice with marshall, not so good with mesa IV.
I'm going to test V30s in M/B & Marshall cab today
I'll post results