Pros: People you don't know and who don't care down at the Dairy Queen can see that you have a lifted truck.
Cons: Expensive, crappy handling due to raised center of gravity, difficult to get aligned--tire wear, ill handling, steering and bouncing bigass tires is hard on steering and suspension components, crappy braking due to bigass tires being stopped by tiny brakes especially on 1500s. Need to alter speedo readings and (probably) headlight aim. Makes the engine seem weaker unless you re-gear, ideally with a stronger rear axle because the craptastic 8.5" axle on most 1500s is stressed under normal circumstances.