http://www.schaefferoil.com/datapdf/9000.pdf See page #4
API Service Classifications CJ-4/CI-4/SM, CI-4 Plus
Global Specification DHD-1,
Like I said I've never used it. I started w/Prem Blue and switched to Rotella - I change every 3 - 4 k miles.
I use Schaeffers Series 9000 5w40, its highly regarded on the oil forums. The only thing I have noticed, in my and other posted UOAs, is that lead seems to spike during its use... something about the chelating effect of a PAO. However, all other wear metals in my single UOA were low. I actually just bought 18 gallons of 5w40 as I intend to change all my vehicles over to Series 9000 for ease of service.
I have also had excellent UOAs on regular 15w40 Rotella... but keep in mind, Rotella is now known as T5/T6, not Rotella T. The only thing I ever saw happen with CJ-4 Rotella is it tends to thicken up viscosity under hard use (boil off?), however; the wear metals still stay well within acceptable limits. And this was when I was towing and already had 20k on the oil.
I use Rotella 5w40 in my Subaru Forester with good results... but as noted, I am switching it over the Schaeffers soon.
Unless you're really working your truck (hard towing or extended periods of high speed), seeing extreme temps (either cold or hot), or running extended change intervals; a quality conventional oil will hold up just fine and you will most likely not see any benefit from a synthetic.