[randomThoughts9]

There are some places where monad composability would improve your code but in general, at least the way I see it, you can replace a scala for comprehension with a set of IF statements, each IF eliminating a wrong value (null, exception, etc). Not to mention that you can have as many options as you like (A|B|C|D|E), whereas the mentioned monads must be composed in order to capture the same thing.

But it's true I never built a big ceylon project, so I can't say I know how that works out in practice.