I haven't purchased "the set" but I do own all the books. There are some monsters in the Monster Manuel 2 that are over-powered, but overall these books bring a great assortment of monsters. I wouldn't worry too much about two the books being 3.0 versions. There's not really enough of a difference between 3.0 and 3.5 to worry about in my opinion. However, if you really want them up-to-date, you can download files that do just that for free from the wizards of the coast website.