As someone who did most of Pimsleur Spanish and Mandarin (and did a single unit in various other languages), and has since continued learning these languages (I'm currently taking 4-5 hours of Spanish class a day in Spain), my two cents is that Pimsleur is fine for gaining confidence in the basic phrases of a language, but is a pretty poor tool if you want to actually learn a language. imo it focuses too much on set phrases without practicing further application.
For adults learning a language, I think you need 3 things to be most efficient. You need to learn the grammar rules/structure, you need vocabulary, and you need lots and lots of content. The specificity of Pimsleur I think is a major blocker. It lacks both vocabulary and content, and there is often a better resource for explaining grammar. I guess maybe the first unit of each Pimsleur course is pretty ok for getting used to the mouthfeel of a language, though.
For Spanish, I got far more out of languagetransfer.org, which helped me understand the concepts of the language much more, and dreaming.com, which gave me lots of content. For Chinese, I haven't found a course I like, but I still think I got more from drilling characters (I made my own app, but something like hanzihero or just an HSK/TOCFL Anki deck is probably good) and using graded readers. I think spoken-first in Chinese is a little bit of a trap, because it's easier to remember things with the written characters, when the relationships between words is a bit more clear.
edit: oh also sidenote, it's been a long time since I used it, but iirc, the Mandarin one is particularly outdated (eg talks about using a phone book) and uses a Beijing dialect, so everyone in Taipei made fun of me the first time I went there.
For adults learning a language, I think you need 3 things to be most efficient. You need to learn the grammar rules/structure, you need vocabulary, and you need lots and lots of content. The specificity of Pimsleur I think is a major blocker. It lacks both vocabulary and content, and there is often a better resource for explaining grammar. I guess maybe the first unit of each Pimsleur course is pretty ok for getting used to the mouthfeel of a language, though.
For Spanish, I got far more out of languagetransfer.org, which helped me understand the concepts of the language much more, and dreaming.com, which gave me lots of content. For Chinese, I haven't found a course I like, but I still think I got more from drilling characters (I made my own app, but something like hanzihero or just an HSK/TOCFL Anki deck is probably good) and using graded readers. I think spoken-first in Chinese is a little bit of a trap, because it's easier to remember things with the written characters, when the relationships between words is a bit more clear.
edit: oh also sidenote, it's been a long time since I used it, but iirc, the Mandarin one is particularly outdated (eg talks about using a phone book) and uses a Beijing dialect, so everyone in Taipei made fun of me the first time I went there.