only used on one trip, but panniers seem to work well, and are good value for the money. I doubt they are waterproof, but we had no rain, so not sure. I brought plastic garbage bags to put things in just in case. Be aware, the panniers came with a note inside saying that they are not recommended for off-road use.
I got these because they have a better attachment system than most inexpensive panniers. The bags look good, but are not the best quality. Still, they should be great for the price.