I feel like I'm at the tail end of that on-ramp, and while I'm still as a whole really appreciating scala, I'm starting to wonder what the end-game is.
Now that I understand and am comfortable with all the functional stuff, I'm left wondering why I still have the OOP stuff, and why some of the FP stuff isn't more natural. I guess you still need some OOP for java interop, but the pure-scala ecosystem is pretty significant already.
I guess what I'm saying is that the easy transition from Java is only a benefit for bringing people in, not for a language as a mature ecosystem. And I'm thinking maybe I should get into one of the full-FP languages.
In fact, if anything, what's keeping me from making the switch is not any OOP features, but actually just imperative! Especially for performance-sensitive sections, and some rare-but-necessary data structures, it seems you really do want a small amount of mutable state.