I have over 400 in my Apple TV library. Quality is great and many I bought as HD have been automatically upgraded to 4K. My only wish would be a better way to organise on the Apple TV itself. On the Mac app it’s possible to create playlists e.g. by director or series. Sadly they don’t sync to the Apple TV box. Scrolling through 400 movies is a chore.
This is what I use. It works perfectly.