per the OP's question of light weight easy on the back do-it all cab: I considered the (2) 1x12 route: I decided for me, I don't ever play where I only need or want 1x12, and it just doubles the amount to carry and ultimately adds weight and size. I also looked at the GB neox2x12 cab--very nice, but $ more, weighs 50% more and is physically larger than the 1212L (which is barely larger than a 1x12). I also did not find the built in wheel arrangement ergonomically suited to me for transport (although I think it could be w/ the addition of a short-throw telescoping handle) tone is all subjective, and I'll admit that I don't care for the 1212L's stand alone tone at home. On a gig however--it is golden! all useable bass w/o any "boom", easy for everybody on stage to hear and sits in the mix real well. so for me, a one-cab one-trip lightweight solution was hands-down the 1212L YMMV IMO etc etc.
PS the one part of the OP's Q I can't answer is the 1212L's suitability for jazz--I haven't done any jazz gigs--but blues and classic rock? hell yeah!