My 2x12 is an Avatar, and I think it's great. It's huge, for a typical 2x12. It's almost the same size as my 1960. I haven't put them side by side, but I think it's considerably bigger than your standard Mesa,
Marshall, or Orange 2x12. Often you look into a 2x12 and the speakers go right to the edge of the framing. Not on this one. It could
almost be a 4x10. Maybe if you staggered the speakers a little you could fit four 10s in it. It's big. And it has a convertible open/closed back. It sounds like a big cab. That's what I've got the Vintage 30s sitting in.
From what I've been reading and with my limited amp knowledge, it makes sense to me that your little DSL would be a good pairing with the Greenback. I'm gonna ramble here for a minute....For one, the amp's tiny wattage almost plays right into a Greenbacks sweet spot. But also, the DSL is a pretty "tight" amp. I'm gonna assume your little DSL has theoretically the same power section topology as the bigger ones. It's got a modern flavor and with Marshalls that usually means a lot of negative feedback in the power section. That kind of sound works well with a loose speaker like a Greenback. And it's also why those old 4-hole Super Leads worked awesome with Greenbacks. They too were tight amps with a lot of negative feedback and why you had to literally crank them to the moon to get them to break up. And like my JVM....it LOVES my Greenbacks. It too is naturally a very tight amp. On the flip side, the master volume 800s, and my JMP, are "loose" amps with supposedly the least amount of negative feedback in stock form from Marshall. The 70s MV JMPs and vertical input JCM 800s are Marshall's most balls-out amps. Not the highest gain, but the most perceived power and punch. They get wild and wooly right away, and they like a tighter speaker like the common G12-65s and G12T-75s.....which each came on the scene right as these MV amps were introduced. It's like the Marshall people realized, hey, these 2203s are murdering Greenbacks, we need something tougher. The JMP 2203/04 era cabs mostly came with G12-65s, the 800 cabs mostly came with the 65s and later the 75s. Generally speaking, of course. You could get Greenbacks too back then, but by the mid/late 70s they made 65s and later 75s the standard, common speakers for 1960 cabs. Those speakers were better suited for the looser 2203/2204s, and my own experience confirms this, to me anyway. My slutty loose JMP sounds better through the "tighter" G12-65s and G12T-75s than it does through my Greenbacks. But really, the G12T-75 is a good all-around speaker that will work with anything, but maybe not sound the best all the time. I have two laying around right now, and will soon have two more when I fix up this B cab. Gimme a little time and if you're interested I'll sell you one.