I used Pimsleur (borrowed for free from the library so cost wasn’t an issue) during my short-lived attempt at learning Mandarin. Usually while washing dishes.
Pros:
I really liked the way the lessons were set up. You’re gradually given new material and then it’ll circle back and quiz you on earlier stuff. I think their system is similar to SRS? In some cases the old material got combined with the new and you have that little “ahah! so that’s what’s going on!” moment. It felt very natural and non-stressful and surprisingly easy to pick up new content without taking notes or reviewing outside of lessons. (Also I’ve been told that my pronunciation was very good, so there’s that too.)
Cons:
The part that drove me crazy was that they insist you ONLY learn through audio! Absolutely no note-taking and NO transcripts of conversations! (I did look for them.)
Turns out I’m a visual learner and if I can’t “see” things written phonetically my brain automatically comes up with its own weird spellings. So I was getting good at recognizing stuff by ear but when I picked up another textbook half the time I didn’t recognize the same words written in pinyin. Which is a big problem if you have to relay on dictionaries or phone apps.
So yeah, good for pronunciation shadowing practice, maybe some grammar. Would not make it my only (or main) conversation learning tool no matter what Mr. Pimsleur claims but overall I was pretty impressed at how much a language can leak into your brain just through the ears. 