Back in Oct. , I installed the Lorenz Bilstein 5100 System on my '03, 3500 SRW with stock-sized tires & about 60,000 miles.
The truck does ride a bit better but, the biggest thing that I noticed was that it takes speed bumps, in my neighborhood, much better. I've hit them, numerous times at abut 25 mph & the system absorbs the shock quite well. With the stock suspension, I would have never hit the speed bumps at 25 mph & the suspension would compress to the bump stops, quite easily. Since the installation, I have never hit the bump stops.
I have not taken the truck on rough/dirt roads, yet so, I can't give an opinion about how the suspension works in those conditions but, I would think that that it would work well.
After the installation, I took the truck one of the best wheel alignment shops in the Phoenix area. The mechanic took the truck for a ride before & after the adjustment. He thought the suspension worked very well. Was quite impressed with it.
Joe F. (Buffalo)