I think the problem with Pimsleur is that the number of topics that you could become "fluent" in explodes once you get past a certain level of proficiency. I do

I think the problem with Pimsleur is that the number of topics that you could become "fluent" in explodes once you get past a certain level of proficiency. I doubt that it could take you to fluency except in a very narrow range of topics due to the degree of repetition required.