No one has really mentioned the Lanikai, so I'll report what I know about it. I have the LBU-C (concert neck, with resonator and brass fittings) and have absolutely no complaints about the workmanship or quality. It plays well (Aquila strings on mine, no reason to change), and intonation is fine, though with a banjolele most of that is up to the user and placing the bridge properly. It is heavy with the resonator on, but I use a strap, and if you take off the resonator (easy), it's no longer heavy.
My understanding of the physics in this case is that weight adds a lot to the sound, because of the design of the head, which doesn't resonate like the normal ukulele top and back...so heavier weight is an advantage as regards to sound and volume.
I don't have experience with other banjoleles for comparison, but I'm not overly happy with the quality of a Luna pineapple I have (Great Wave painted). The intonation is not good, though it may be better after I do some nut and saddle work eventually. (not wild about their logo either, but that's no big deal). I'd probably look at the Eddy Finn version before the Luna, but there may not be any basis for that aside from the above. The only thing I can see against the Firefly (given the quality of Fleas and Flukes) is those peg tuners, which I really don't like (I guess some like peg tuners, but for speed (in tuning, not changing strings), ease of use, and accuracy, I think they're a hassle). And no resonator, if that matters. I like the option of having a resonator, but you can save quite a bit of the cost by getting one without it.
I got my Lanikai from Butler Music for about the price of the Luna you're looking at, as a factory 'blem' because of some minor scratches on the resonator wood (which buffed out very easily), but they're normally priced about halfway between the Luna you're looking at and the Gold Tone models with resonator. I'm very happy with it, but as I said I have no experience with the other brands for comparison.