To improve the ride look into a custom set of springs. These leaf springs were made when the technology was not as good as it is today. any spring manufacture can make a new spring for you cheap too. The pleasing ride of the newer trucks is the springs. nothing more. Some of the new trucks weigh more than our older rigs but they ride better. Its the springs be it coil or leaf. They don't last forever too. they do wear down.
Gary, I have to disagree a little. Yes, the TTB frontend is better when everything is in good shape including springs, and NO ADD A LEAF! 2 leaves is enough, but no matter how you look at it, it has no travel and inherent "binding" to wheel travel. Rugged, but no wheel travel.
Yep. I inhereted a 2002 F250 Super Dooty for a company truck in place of the 86, now that I'm up here in Montana. My son got the 86 as a gift. I wouldn't have wanted to drive it in the salt anyway. The 2002 rides a little better than my wifes 96 with stock F350 springs and D60. Not enough to make ME want to own a SD though. You just trade one thing for another. Not being able to get to the back of the engine, and having non serviceable wheel bearings are 2 big reasons I don't have a newer truck in my personal fleet.
If you really want to have a D60 conversion and a nice ride, take a look on Powerstroke Army and Powerstroke Nation at the info on doing a reverse shackle kit designed to use Super Duty 99-2004 springs. With the right shocks and sway bars you have 2004 handling with no downside.
Unless one trades in vehicles before they need to be fixed, the only real other choice is to find something to stick with. If you are determined to keep up a vehicle and decide it is it, it will be way better tha trading for another used vehicle cause you always end up in the same place.