I'm VERY biased, and this is a question likely to get you a million subjective answers, so here's my .02:
For banjo uke, the Eddy Finn is OK. I've played Gold Tones, Morgan Monroes (same manufacturer as Eddy Finn) and Lanikai - They are all more expensive than the Eddy Finn, but I don't think they're that much better. I think upgrading to those more expensive banjo ukes doesn't get you value for your dollar.
For new, I really DO like the Firefly, and I'm very excited with what I've seen of the Mainland. The only other new uke I've played that I'd want is the Beansprout, and that's $1,000+ depending on the model - they're GREAT.
If you're not afraid of going with a classic vintage uke, I recommend the Gibson UB1 - they're plentiful, relatively cheap ($300-$550) and sound miles better than the Gold Tones, MMs and Lanikais. The Gibson UB2, though rarer, is even better, and is very good value in a top of the line vintage instrument, ranging in price from $400-$550 these days in a depressed market. The UB3/UB2 Deluxe will run you in the $700-$1,500 range. The UB3-4-5 resonator ukes in good condition run about $2.5K and up and are too steep for me.
The other vintage model I'd recommend for the upgrade on banjo uke is the Ludwig Wendell Hall Professional. If you can put aside between $800 and $1,500, you'll find that they come up for sale several times each month and just sound fantastic; nothing's better in my opinion, except the Ludwig Banjo Ukulele and MAYBE the Gibson UB3-5 resonator models.