Mac users do tend to install OS updates more quickly than Windows people due to the stability of the mac os and the yearly cycle. Microsoft tends to focus on a 5 or 10 year cycle with major changes (and a generous supply of impressive bugs).
However, wise mac users wait for one or two bug fix updates to a new version and check what expert software reviewers say about the OS. This puts cautious users in a December timeframe after the normal yearly late September launch.
It is amazing to me how many people install beta OS versions and stand hours in line for the newest iphone, etc. Such cannon fodder paves the way for the rest of us.