In my opinion, thee is nothing wrong with a mild lower, whether 4x4 drivetrain or not.. I all depends on your purpose/preference.... although I will say this: Bagging and tubbing a truck, any truck, (or any vehicle what so ever as far as I'm concerned) looks absolutely retarded in my opinion. Most especially a truck, a truck is supposed to be roomy, higher off the ground, able to carry loads and do work that a sedan or something is unable to do. Putting tires on it with a 1-1/2" sidewall and getting it so the body of the truck is like an inch off the ground is just completely pointless to these vehicles. I mean, people like what they like, put it always brings a tear to my eye when I see a once tall and proud truck with it's balls chopped off sitting on the ground.
I really don't plan on doing anything to the suspension in mine, but if I DID do anything, I would lower it like 2" or 3" all around. I'm building a drag truck, so the extra lowered stance would help in the aerodynamics and center of gravity department. I DO plan on building an offroad truck down the road with some 33" on it and a nice 4" - 6" lift.