Sorting lists list should also be available on profile page, personally I'd like them to be sorted by book count inside particular list. If I am interested in some book and if it's genre is one of those I read most often, I'd want to have this list shown at the top of both "Add to list" menu and "Lists" section on my profile.

The current way where it doesn't auto-sort is definitely easier when adding books to lists (I have many, many lists and it got really annoying getting sent to the top and having to scroll back down again every time I selected a list), but it is definitely easier to check what lists a book is already in when they're all gathered at the top. Maybe after a page refresh or something they can be brought to the top? Best of both worlds?