I'm a Java dev in my day job, and I have to say that as a beginner in both Haskell and Scala, I surprisingly find Scala far more difficult than Haskell.
Scala's type signatures are even harder than Haskell's (or at least, mixing FP with OOP makes them harder for me) but you don't get the same guarantees about side-effects and the type inference doesn't work as well. And implicits scare me.
Scala's OOP may be good or bad, but it certainly adds an additional layer of complexity, and one you can't ignore when reading or using someone else's code.
Scala's type signatures are even harder than Haskell's (or at least, mixing FP with OOP makes them harder for me) but you don't get the same guarantees about side-effects and the type inference doesn't work as well. And implicits scare me.
Scala's OOP may be good or bad, but it certainly adds an additional layer of complexity, and one you can't ignore when reading or using someone else's code.