Its about ~2-3GB for a movie for me. The Quality isnt great but still better than Netflix streams.

I use Symphonium for a year now and it is all I ever needed. Has all bells and whistles, great support and all of the features you could wish. A huge step up from the native app or even findroid and the likes.

Jellyfin + Symphonium as a client on android 💯

I hear that public trackers are pretty good. But if you have a lot to upload, getting into a private tracker gets you a lot of credit, so you can download more high quality stuff.