Indeed. Though with variable arity (which can be a good thing!), currying will always be at least slightly more cumbersome than in languages with fixed arity of the ML type syntax for function application.

Currying and combinators are my preferred ways of creating new functions. Having infix symbols can help a bit, but I don't see it as crucial.

Incidentally I only really began to use reduce/fold in Clean and Haskell, though I had been exposed to the concept in Scheme before, and used it a few times. But perhaps that was just a learning effect of prolonged exposure and would have happened while staying with Scheme, too.

I still like Scheme. Matthias Felleisen is doing great work using it for education.