I got the wrong type of cheap REI pannier and had to take it back to get some Ortliebs. Sometimes you gotta pay the money. Was trying to avoid that, but I had to give in. Just remember.... it's cheaper than driving.

Also, Ortliebs are much more cooperative if you get some Eagle Creek Cubes or drawstring bags or binders and folders to organize the contents. That's why they can get away without the dividers...