My 09 GMC Sierra (double cab/short bed) drives very well with no load or with my kids and dog in the cab. The problem is that using the truck as a truck (loading any substance into the bed) compresses the springs too much and the truck will crouch and roll around. In fact, a load of mulch or a foot of topsoil makes me drive bumpers. So I thought timbres would be a great solution to my problems. Increase payload without sacrificing unladen ride quality. That's why they're not the answer for me: for hauling a load of mulch or dirt, they work like a charm. Once loaded, the truck's leaf springs compress and the wooden "springs" kick in - they support the axle, and the truck barely squats. The truck drives very stable and the ride is not that bad. (important - if you slowly walk home from the children's room). But, and it's a big but, when I load up my kids, bikes, firewood, coolers and the like and plug in my retractable RV, the springs compress, the tonal colors take over and I get stuck in a horrible wobble. travel hundreds of kilometers. Every hit and bump in the road is transmitted directly to my seat. So the Timbren SES does exactly what it was designed to do. However, I may have problems with my springs and dampers, or my application may just not be the best place for tone blocks. If I was *just* lugging around dirt/rocks/mulch I'd be 100% happy. Hauling the trailer and gear was an awful experience and these tones are going to be flying off my truck tonight!