By and large, I have found it to be a very useful site for finding good quality revision notes. Some of the notes do seem a bit lower in quality than others but with the previews, you can always tell before you buy.
People complain that you cannot download and print the notes - yes this does make things a little more convenient but the quality of the product is what matters most. And thankfully this site as a lot of very good quality, and so very useful resources! They always have offers on too and like to circulate discount codes which is a nice bonus.