I have been using Timbrens since 2006, and chose them over the Sumos because of the rubber construction vs the poly construction of the Sumos. I used the double convolute on my 2005 1 ton and then tried the single convolute on my 2015 dually.
Didn’t like the single convolute so I talked with Timbrens, after looking at different double convolute specs, and they sent me a set double convolute that I felt would ride softer and allow the truck to set level at full load.
I am very pleased with my setup and you can’t beat Timbrens for their great customer service.