After fairly long time playing with Haskell, I find it quite beautiful and pleasure to use, but only for theory/book-ish use cases. As for real world usage - it is quite ugly and cumbersome, e.g. when you need some error handling and multiple monads using (with transformers), etc...
Another quick way to measure this - compare that beautiful pseudo quick sort to real quick sort (e.g. using Array.ST)...
I have to say that I agree with you. In principle, I find the notion of an effect system extremely powerful, both for safety and optimization, but Haskell's way of intermingling effects using monadic towers is terribly awkward and cumbersome, not to mention that it comes with a mental cost.
Another quick way to measure this - compare that beautiful pseudo quick sort to real quick sort (e.g. using Array.ST)...