Office has a zillion features buried in various menus and panels. The help feature has been pretty reliable when I need to find something that I know is in there.
I have never once found an answer in an F1 help in a Microsoft product. And I've been using Windows since 3.0.
On a somewhat related note: Before wiki's, google, and stackoverflow became the norm, I used to love downloading CHM (compiled help files) references for HTML 3.x, Javascript, C/C++, and more.
Really helped out a young kid figure out how to write autoexec.bat/config.sys files so that his games could run. Being able to write menus so I could customize my setup for each game was so amazing.
With the advent of the internet the quality of on-system help documentation has stagnated.
Then it became uselessly slow.