I had actually never considered a longneck soprano, because I also thought "why not just get the next bigger size?", but then I discovered and wanted a KoAloha soprano for the big, full, but traditional sound they have. However, their sopranos only have 12 frets, which was a bit of a deal breaker for me.
The folks here on the forum suggested a longneck soprano, which I wasn't really keen on. Seemed weird to me, a little Frankenstein-ish, not something I wanted. The consensus among the community, though, was that nothing sounds like a KoAloha soprano but a KoAloha soprano, and the closest I could get and have more frets was with a longneck model.
While still squirming, a local vendor here in Germany turned out to have a KoAloha longneck pineapple soprano in stock, which is pretty rare over here for anything from KoAloha. Normally, you have to go the import route and pay nearly a third of the original price for taxes and shipping. He, an accomplished player himself (
Andreas David), was very enthusiastic about it, calling it "phenomenal", and so I figured I might as well try it. I could have returned it, so there was no real risk.
And wow, what a darling it turned out to be! It did have the sound I wanted, and it did have 17 frets! While it lives in a concert hardcase and doesn't fit in a soprano one (mostly because of the body shape), it feels very much like a soprano, but does give me the fretboard of a concert (just as narrow as a soprano neck, just a little longer, but we're not really talking about three foot here, you have to look for it to notice it).
I would probably have been just as happy with a concert model, but the longneck soprano was just closer to what I had envisioned and wanted. It came unexpected into my ukulele life, but I feel it was a fortunate event. You should try one!