I've always found Lingua Franca Nova really charming for some reason. I've been trying to learn it on and off for years now. Yeah, I like how it sounds, and I see it as far superior to Esperanto (even if it does have some Euro-centric bias, such as how it forms passives), but really I have a hard time convincing myself to learn a language where the only thing I'll ever use it for is reading a translation of Alice in Wonderland. And don't ask me why they would choose to translate something that's so heavily dependent on word play, which obviously doesn't translate well. The only advantage to it is that its in the public domain, but was it really their best option? Seriously.
I know learning languages is supposed to exercise your brain or something, but frankly I don't see Lingua Franca Nova being much of an exercise. I mean, the grammar is simpler than Esperanto and even if you don't know the language you can probably recognize 90% of the vocabulary just because its a posteriori.