I'm glad that the library features were added back. I really like those and find find them very useful.
I'm not sure if this has been addressed or not, but sorting your completed list by progress still is not accurate. I prefer to keep my list sorted this way so that I can look back and see which anime I've recently watched. My completed list has some anime at the top that I watched months ago, so it's not sorting properly. It doesn't seem like it is sorting it out by the date you finished watching.
Also, another thing I noticed that I believe is adding to the issue above, is that I have re-watched some anime, and I think due to the amount I have re-watched them, they have been bumped up my completed list accordingly. I noticed also that if you go in your library, click on an anime, and add to the amount you have re-watched it, it will move that anime up to the top of the list, which never happened on HB (it would remain in the same spot as when you first finished watching it).
I know these are not major issues, but it's just slightly annoying when you want to sort your anime by the date you actually finished watching them initially.