IMO I would always rather have syntactic sugar in Haskell, since parse errors are usually not the kind of bugs that one keeps making. If I encounter a parse error, I would probably not write code that leads to the same parse error ever again since there are so few of them I've encountered that I need to keep in mind to avoid.
I remember thinking figuring out the indentation of a where clause was almost impossible in Haskell since I constantly was getting it wrong at first, but now I almost never make a mistake using the where keyword.
