I bought slip cases and binders from Archival Methods, and they are good products. I still have some sets in them, but I have increasingly moved away from binders in favor of of cards/sets in toploaders/Card Savers in boxes. I didn't do this because I'm afraid of damage, however. I've successfully stored cards in binders for decades with zero issues. The reason I have shifted strategies is due to the fact that I am starting to collect more variations, and I don't want to worry about having to rearrange an entire binder set when I didn't leave enough empty spaces for the variations of a given card. My OCD demands that the variations of a card all be side by side and not have some at the end of a set. I know I'm weird.
I also like being able to "play" with my cards when I want to. I like arranging and then rearranging my early 50s sets. Sometimes I want them in chronological order, and sometimes I want them arranged by team.