I have Rosetta Stone for many languages, and have personally done (or am currently learning) Spanish, Portuguese, and Mandarin Chinese. I find that for the simplicity and ease of the software, it really works. I know Spanish and Portuguese might not be a good proof, as theyre similar and I knew a mediocre Spanish before I started, but Chinese is a unique language and it works just as well. I don't have time to do it every day, and even when I do I only do it for about an hour, but I would highly recommend it.