Besides their being archival, the best thing I love about Print File binder sleeves is that they're easier to get the negative strips into them!
While visiting St. Louis last fall, I stopped by a shop and found a 100-pack of 35mm binder sleeves made by another company on clearance. I could barely get the negatives to fit and I nearly tossed out the whole pack in frustration! Print File's sleeves are so much better.