I have them. They're great. They don't affect the handling at all since they are normally not in contact with anything. They only come into play when you are loaded down. Then they work perfect. Easy to install. Very nice quality. I got mine on Ebay from a place in MA with free shipping.

These are what I have:

http://www.timbren.com/timbren-application-guides/application-pdfs/FR150SDE.pdf

The second page shows how they work basically. I am not sure if you are talking about the same application. These I have are to increase the load rating of a truck. Obviously doesn't improve the brakes or tires...

However they don't "soften the ride" since as I said they are not in contact normally. But they leave the ride normal, which add on springs would make it very stiff. So maybe that is what they meant. Or maybe a different application.

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1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra