Even on rough gravel this has been awesome and trades between all my bikes. I have been a big fan of my fidlock stuff but this has been one of my best bike purchases.
One of the things I like about Fidlock is how well their products deal with an n+1 scenario. I just bought their saddle bag and I wanted a way to use the same saddle bag for both of my bikes. With Fidlock, these sorts of accessories and extra mounts are very reasonably priced. I bought the mount, threw it on my second bike and condensed from two saddle bags to one that I can easily swap between bikes. It's a simple installation of a single screw (assuming you have the correct size Torx driver).