Lately I've been reading a lot about functional programming principles and how they (of some of them) can be applied in C#. So I came across Language-Ext and CSharpFunctionalExtensions (as well as a few smaller ones). I briefly tried Language-Ext and am liking what I see, but haven't tried the other. I know there's always F#, but I want to explore other options as well.

I'd love to hear about other people's experiences with those libraries (or similar ones). What do you like about them and what don't you like?