I love these binders. You have to be careful with the cover plastic as it can tear when inserting a new binder cover inside. I've never had the binder corners rip and I use them everyday during the school year. They hold up very well throughout the year and although I haven't put 600 sheets of paper in them they do hold a lot of paper (and get heavy). I wish the stores carried Red in stock so I wouldn't have to order it online only.
Attractive binder that is missing a couple of features - it is not gap free so the paper does tend to get stuck in the rings and it is missing the hard rubber or plastic sheet that makes it easier to move all the paper at once to close the binder
I have lots of different binders but every once in a while I treat myself to another of these which I've bought in various sizes. My past-years bank statements and other such documents can go in the cheap binders. But for anything where I frequently have to add more stuff or for material I review frequently these make dealing with the paper avalanche slightly less painful.
I bought three of these on the buy two get 1 free special one blue one orange one pink. I too the blue one out the bag about a week later and it just did not seem as strudy as the regular black binder. I open and closed the prongs and they are acually loose. The check it I touched the prongs to see how stable they were and it moved with really no effort. I checked out the other two colors as well. These folders just seem to be a bit flimsy and not as stable as the regular black folders. I really do not like them. I want sturdy and durable within reason.