I bought these bags to supplement my Kreiga US40. They fit easily and were secure on my Ninja 650R even at interstate speeds for 500 mile days. They didn't interfere with use of the US40. They hold a lot, and the length allows for a sportcoat to fit rolled up so it won't wrinkle. I have not been provided with an opportunity to test the waterproofing, but I'm not sad about that.
Drawbacks are that they might rub on the paint if not very tight; they might loosen up slightly after some distance, but I never found more than about 1/4" of play in 100 miles; and I don't care for the muddy knobbie tire track graphic, but its fairly subtle. (Posted on 8/9/12)