Ortliebs are cheaper, waterproof, and have one huge pocket.

Arkels, while I haven't tried them, I have seen them in person, and if I had the money wouldn't hesitate to get them. Even though they don't have a rubberized material, they claim waterproof on the description. I believe them.

Money no issue, you just can't go wrong with an arkel product. I have the handlebar bag and love it. It doesn't claim waterproof, but I've been through a day of riding in the rain and not a drop, so take that for what you will. I also think if you like order to things, then arkel will probably be a better bet. (OCD level order)

Things tend to need extra little stuff sacks and whatnot to keep everything organized in the ortliebs. Still, they're durable, and on sale, can be very cheap.