Couple of quick observations:
I finally tried my MAS 112 on its side, angled up 15 or 20 degrees with a foam wedge underneath. Just did this at home (I am unlikely to play a stage that will allow for this soon) but it really does make a difference. Some more bass (even on a carpeted floor), a bit more plush feel to this tight and focused cab, and, most notably, more of the 3D effect -- felt a bit more like the Flex in that regard. The 112 has always had a clear sound and excellent dispersion (sounds even out in the house), but, to my ear, is the most traditional sounding and least obviously "3D" of Mike's cabs that I've played (I haven't played the Faital and LPT variants of the 112, or the 109). Turning it on its side... not a night and day difference but there was something immediately noticeable -- more open, relaxed, enveloping -- in the presentation. My brother actually likes it better vertical. Will have to play with this some more.
Of the Flex, 112, and the 46, the 46 is definitely the most hi-fi. Beautiful cab but, with my Fender, I've found myself leaning toward the more forward and textured mids of the Flex and the 112. Yesterday, I played a very modern-sounding (think "piano-like") six string that I'm trying out, through all three cabs and, to my surprise, liked it best through the 46. I say "to my surprise" because I often find myself doing a yin/yang thing with gear -- fat amp that's big down low? Pair it with a tight cab, etc. With this bass, though, the 46 seemed to enhance everything it did. It sounded good through the other cabs, but the 46 seemed made for it. I dont' know if it's so much a yang/yang thing (which is how I was tempted to think of it before) as strength complementing strength; the extreme clarity of the 46 just allowing everything to come through. And while all these cabs are quick and articulate, the 46 is probably the most plush down low (esp. with the sub, though I was playing it on its own) and the least "dry". ("Dry" here meaning zero overhang to the notes -- the 112 is the driest cab I've ever played, in that regard; the 46 not as dry but still quick and clean; and the Flex between the 46 and the 112 in "dryness".) That bass is very dry -- good sustain, but not a lot of ring from the body -- so maybe a nice yin/yang that way, if that makes sense. The sound was clean, clear, and full.
Side note: I'm not convinced of the B-string on this bass. I have a hell of a time finding a B-string I really like -- wonky overtones, man. First world problem, I know.