5 stars: Great selection, app actually works fine. When you've exhausted all the podcasts you want to listen to, this is where to go. But you really need to fire all of your IT staff, the app sucks. I reactivated my account but it doesn't recognize that and keeps trying to get me to do so again, and when I try to send a note through the app it tells me I'm not connected to the internet. It's very frustrating and downright idiotic.
4 stars: The Great Courses is, well, great. The app is a a bit less so, but it has improved significantly over the past two years and is quite usable now. Audio is no longer a second class citizen, and casting audio works well. My biggest wishes are for Android Auto support for listening in the car, and for Android TV support (they already support Amazon Fire TV).
2 stars: The contents of the courses are good, but I planned on listening to the lectures on my walks and on my commutes. However I can't just listen to a downloaded lecture without having the video player running. Background playback is only supported on the audio player, which cannot be used with the downloaded videos, and downloading audio is not supported (?)
2 stars: The content is amazing, the app is horrible. I seem to be only able to reliably watch the videos on a PC through the web browser. It crashes on my Samsung tablet and the Roku version constantly crashes. Also a number of updates have wiped out my password and I need to reset it. No, I did not forget my password...