I think the current list-by-author is good, it is sorted first by author, then by series and index (if any), then by title, which is exactly how I orgainse of books in my head.
However the current list-by-title which sorted first by series (if any) then by title, is not very useful. I don't often use list-by-title, but when I do I think I would prefer not to have the list sorted by series. The series information is still displayed in the list, which is all I need.
So I would prefer list-by-author is left alone, but change list-by title.