Love my Firestone 5000s but it's not really the brand I care about.... it's the concept of the bags. They really stiffen up the hinge between truck and trailer or 5th wheel. Also, super nice if you ever need to load up with gravel or building materials. As all the weight Nazis are quick to point out, bags don't increase your payload and that's true. But they sure do make life up near the max a lot more manageable.
The main thing is the ability to adjust the psi to fit your situation. Timbrens are just a one size fits all approach.