I like RS a lot. I like the immersion style of teaching. There is no spoken or written English in the lessons. Immersion and conversation are the only ways to become fluent in a language, IMO. I'm also doing Duolingo, but there is a lot of translation between English and Spanish. It makes you do the translation in your head instead of teaching you to think Spanish. The only complaint I have about RS is that their speech recognition software could be a lot better. Sometimes if I completely mangle a sentence, it gives me a perfect score. RS is only $120 per year, and I don't plan to use it for over that. There is also an iPhone app that is free. It will cause a little eye strain.