The bags are awesome but the mounts are crap. Your truck may have a different setup than mine but, generally, it will be the same. This picture is after one trip down to the coast (Big Shell) for some fishing.
The bracket bowed out which also caused the saddle not to sit on the axle straight anymore.
In the pic below, notice that the tab is bent downward where the bags bolt to the mount. The bolt sheared off and the tab bent downward.
I have a gooseneck and at the point where the upper airbag mount attaches to the frame, the airbag mount bent and dangled my airbags at an angle since they were no longer attached at the bottom, either.
I didn't even notice all of this until I got back from the trip. I had to remove the brackets and weld in supports. They work great now but the mounts that come with the Firestone bags, for me, were crap. I'm pretty easy on my truck and it's in excellent condition so this is not a case of abuse.
I have the Viair OBA sitting in my garage just waiting to be hooked up. Haven't had the time lately.
I highly recommend welding in some additional supports on the brackets due to my personal experience. There will probably be people that chime in and say that they've never had a problem with them so take everything, including my experience, with a grain of salt.