Never used them, but I have read they are very good......far from the cheapest at $200+
Depending on the language, there are so many free resources out there, and some ways that in my opinion are vastly superior to structured learning. I could not get into the 'sit and study' thing to learn english, so found things I enjoyed doing [forums, mags, TV etc] which made it more bearable. If $200 is no biggie to you I would say go ahead an get it, but if you prefer to save funds maybe look at other methods..as imo they are better anyway.
What language are you trying to learn?