Thom,
I think Aquila does this just to confuse us! They make two sets: a banjo uke pack with a wound third string, and make a second set without the wound string. Aside of the wound third, they are the same set of strings, and the only difference between these and regular Aqulia soprano nylgut strings is the string gauges, which are slightly heavier in the banjo uke strings.
I'm not sure why they do this, as the regular soprano nylgut strings have been better sounding from my standpoint. As for the wound third, I see no real benefit. It doesn't really make that big a difference in tone - it sounds ok, not particularly twangy (and let's face it, does your banjo uke need help sounding twangy?), but regular Nylguts sound better to my way of thinking, or hearing. Right now, I've got regular soprano Nylguts on my Wendell Hall (which are great), Aquila Banjo Uke strings on one of my Strombergs, and genuine Aquila Gut strings on my Slingerland model 20 (which sound very 'vintage-y' and great!).
I've also used Worth clear mediums on another Stromberg and on a little Tonk Brothers banjo uke I just sold, which are very similar to the fluorocarbon Martins, and gave a great sound - a little less percussive and richer. These sound particularly good when tuned up to D and Eb tunings, better than they sound in regular C tuning.