I got them earlier this summer and have almost 700 miles on them and they are still in fine shape. You can see a bit of the waterproof coating is coming off after a 20mph dismount, but the inside of the bag still doesnt get wet. Sure is nice to be able to carry papers and such without worrying about them getting wet.
Only downside I can see is that you'll be tempted to bring so much extra stuff because they're so big.