I only have three gigs before my 30 day return policy runs out...
I don't think the time frame will be a problem. I think you'll easily know after the first rehearsal and gig if it's your thing or not.
Now live, I really liked...
First of all, yeah, the CA-9 is KILLER, and yeah, the UL502 IS a world class amp. IMHO, these are two immutable facts.
However, IMHO, the MB is also a world class amp.
You have to remember a lot things go into determining the price point of an amp, and in this case, we also get to throw in world market economy effects. So even if the LMII uproots the 502, there's no reason to feel weird about it.
I have a Stewart 2.1, and it is, IMHO, a VERY close second to the CA-9. Killer amp. I've been using a Crown Xti-2000 most recently, but not because I think it's a better amp... only because it fits a shallower rack, and honestly, it really is a great amp too. In fact, one of these days I need to A/B and see if I can even tell.
One thing, however, the LMII does not do well to drive a power amp. The DI out is fine for boards, but isn't really hot enough to drive a power amp to max output, so if this is a big deal to you, you need to think about that. I also do this, so when I need big power I actually switch over to the Eden 405 into the Crown into my UL310 pair. OT, but must be heard to be believed. I love that rig.
However, for simpler rigs where it's just a head and a cab or two, man, I LOVE the LMII. It pairs particularly well with really dynamic instruments like Skjold, MTD, Zon, Celinder, etc.
When I first got my LMII I still had a pair of really nice 210 cabs and it blew me away.