The Jannd Commute pannier is a very nice bag and the mounting isn't as quick as Ortlieb, but it's stable and perfectly serviceable. The material is similar to that of fabric used for backpacks so it's fairly durable. Three zippered compartments so it's a great way to separate stuff in your bag. I've never tested the water resistance since we are having a drought in California, however, you can always line the inside with a garbage bag to waterproof the contents it; it worked for my ruck in the military...What I don't like is that there are a few inches that stick above the rack when mounted and that portion is rigid. It makes it awkward to carry large objects that need to sit flat on the rack like a pizza.

I also have the Ortlieb Back Roller set and I like the quick on and off mounting system. I like that you can over stuff them by not rolling up the top, but gotta be careful that it doesn't flop over and spill the contents. I don't like that it's one large cavernous pit with only a small pocket that will hold a few papers inside. Opening and closing the bag is a little bit less convenient than than just sliding a zipper. These are waterproof both ways, don't spill anything inside!