It is great that you can have only one style sheet with which to change all your pages. It will definitely save time.
I tried looking for a "bad" website, but that is difficult, as I don't know where to start! I will, however, be looking at websites much more critically than I would have before.
I've really had to battle this one out. It has worked on some of my practice projects but not others. It works on my Illuminati project files, but not my Parrot project files. I have not been able to link it to my personal practice project 1 which was developed using html. I have however out of frustration started a new practice project from scratch developing the site using a linked .css master styles file and this is working perfectly. It is also amazingly time conserving compared to the laboriousness of setting up project 1 to this point.