I think all of my sandpaper has gone bad. It's all got bumps all over it, makes it all kinda scratchy. :-0
I think my path is a lot like Bruce's. I have a pile of what used to work, or at least what I bought, and I too saw the videos and now have a shit-ton of Cubitron. I'd have bought way less if I had known Extract was coming right behind it, because it is clearly even better per the testing, but if you could buy Cubitron for a LOT less, it still kicks major Buttocks over ALL of the others before it.
My only beef with either of them is edge sanding, on an edge you want to keep sharp. If you slightly catch the corner of those sharp edges it just shreds the disc you are using. All discs will kinda do that, but not as completely, or as easily as Cubitron, and Extract. Thin and all those holes that make it a super sandpaper, also make it kinda whimpy.