Syntax is by far the most superficial difference. If you're going to actually use functional programming, the trick will be learning the paradigm and not worrying about syntax. In fact, from that perspective, I think Haskell syntax actually wins out: it's extremely simple and very well-suited to functional programming. I found things like curried functions and recursion much easier to grasp and use in Haskell than in Scheme when I was learning both simultaneously.

I certainly do not think that syntax is anywhere near why some people find Haskell hard to pick up. Thanks to pattern matching, the syntax is very visual and thanks to having relatively few forms and keywords, it's much simpler than most imperative languages'.

Also, I'm not suggesting necessarily using Haskell exclusively, by any means; I just want more people to consider it at all!