There are real pain points in Scala when you try and scale it from single developers to teams working on a project and most of them are to do with the flexibility of the language.
I think all companies working with Scala end up settling on a sub-set of the language that they are happy with. In that sense, the bad is irrelevant: you are never put in a situation where, say, you are forced into using implicits (apart from light use in external libraries like lift-json) so if you don't use them you never suffer their downsides. If you obsess over parts of a language you don't even have to use... then well I'm afraid I have nothing but scorn for people like that.
At team-scale then your main pain point is trying to get style of writing that everyone can get behind. Code reviews can be painful when developers with different ideas on how to solve a problem butt heads and pull requests turn into "That's not how I would have written it" instead of critiquing the actual code presented.
The tooling and compiling I completely agree with. SBT is a horrific mess. I don't have a single good word to say about it.