I like that it's very easy to use reactive programming in java, especially when you know how rx works with monads or observers patterns are great! It gives me some peace of mind knowing my code will be more maintainable because i'm not implementing every part manually anymore (i still do but most things).
There isn't much out there about this lib so far as well which makes finding jobs difficult too sometimes since employers want experience from working at companies who used these libraries before them..it can get confusing if your new into software development :D But overall its really fun once u become familiarized w/rx!