The 05 SD have gone to a coil spring front suspension. This will no doubt soften the ride. And it cuts the turning radius down by 5.5ft. That was the 2 biggest complaints that I had with my 99,rode too stiff and you need a mile to turn around. You really cant compare the ride between an IFS truck(Silverado HD) vs. a solid front axle truck(SD). Thats apples to oranges, the GMC is gonna ride better but for extreme use the Ford will hold up better. BTW I have always been a Ford man,my H2 is my first non Ford vehicle,and I have taken alot of **** for it.