I like both Python and Ruby. I agree with your summation that there isn't much to choose between them; except for blocks/closures, but for me that is all the reason I need to choose Ruby. Blocks are an astonishingly powerful tool that transform the way you write code and interact with a system.
Until you have experience of them you probably won't get how powerful blocks/closures are. I'm generalising from me, because I didn't get it for a long time, to you. Probably unfairly.