After a little bit of use, I feel like lodash-fp is limited by being a simple adaptation of lodash. Lodash's API is designed around variadic functions, which doesn't really work with autocurrying, so a bunch of important options and functionality is lost. On the other hand, working with Ramda makes me miss some of the flexibility of lodash - e.g., not having to use a different map() for arrays and objects.
The optimal functional utility library would be designed with autocurrying in mind from the start, but not shy away from flexibility where it makes sense.
prelude-ls really shines when combined with LiveScript - syntactic support for partial application, currying, function composition, "pipelining" (|>), implicit arguments and so much more really make a difference.
That being said, I'm very interested in mori, immutable-js or lz.js. prelude-ls is nice, but is designed to work with native JS types and provides no extended semantics that I'd find useful. It's still my go-to library when working on the frontend and it probably will remain one, but I'm thinking about contributing some support for other advanced collection types to it.