Did a 500 mile trip in my 06 and it wasn't awful, but wasn't great. Put these in, thinking they might make a difference. Immediate improvement. These make our first gen tundras more comfortable than a 2nd Gen.
We love the Rear Jackers added to my son's Toyota Sienna. I have a bad back and need a flatter surface to sit on. The rear jacker's raised the seat 1 & 1/2 " which made a huge difference to the comfort of my back and my daughter in laws. We are grateful 'Desert Does It' came up with what I was wishing someone would.