Its not just the content, but the container.
The current Qt help container has lots of bugs - and has been mentioned that Slick has been unable to resolve.
Of the most annoying problems:
Bookmarks: These sort of work, but they are always lost on updates - making them useless for me.
Sync With Contents: Mostly doesn't work - works for some pages, but lots of pages it doesn't work for.
Poor indexing and searching.