Great article Astrid, thanks. I worked for many years (on and off) on Spanish. I hope to learn Mandarin now. I think another factor that makes a big difference is the teacher and the teaching techniques. I had an incredible Spanish learning experience in a four-month "immersion" class with a gifted teacher. At the beginning she was like a little clown, acting out emotions, animals, etc. Gradually she changed as our Spanish improved and by the end of the class she was speaking to us in complex sentences at normal conversational speed. Unfortunately Mandarin instruction has been stuck in the rut of trying to teach writing and speaking simultaneously, which I find slows down language acquisition and dulls my motivation. However, there are now many creative online resources (such as yoyochinese--google if interested), that teach Mandarin in a fun way that builds a solid speaking/comprehension foundation before moving on to an excellent online character-writing class. Good luck to all of us in our quest to communicate with more of our world's population!
