Sounds as if there are some bits of the article that could be tightened up or corrected, but I found the article very helpful. It's been about 10 years since I've coded in a C-style language (Java, C#, C++), but I'm very familiar with significant-whitespace languages (Python, Haskell, Coffeescript). The C-style-ish-ness of Rust has colored my perception of the language: the features sound great... but it looks like C? Admittedly, an unfortunately shallow perspective, but we've all got a lot of ground to cover and the view from 10km is necessarily incomplete.

The article's side-by-side examples really opened my eyes. I understand that Rust doesn't implement all of the functionality of Haskell, but it's comforting to see analogous functionality. So Traits aren't Type Classes; but as a beginner in Rust and as a first-order approximation, I can hear sorta-Type-Classes when I see Traits. That'll get me past the first steps, then I can dig into the detail of Traits.

I would suggest the author include a section on Side Effects since that's a big talking point around functional languages. Some allow them pretty freely (Ocaml) and some don't (Haskell). The only place I really see mention of this Big Deal is a little header to a code comparison saying "Recursion with side effects:".