Having done both professionally, I'll take Python any day of the week. The "Expressivity" lauded by Ruby fans translates into a lack of readability. But the things that drives me crazy is the optional/alternative syntax of ruby.
Ruby is a lot like spoken language in that regard. When the many ways in which to do things are chosen well, Ruby reads like pure poetry. For that I will always enjoy Ruby.
Moreover, the choice of which idiom to use conveys the intent and mindset of the author.
But like any complex language, it's also possible to write very unpoetically, and like any complex language, readability is a function of familiarity with the language's syntax and idioms.
