The 1.5" is actually perfect for the 1500, IMO. It is A LOT of work to go through for a mere 1.5" but a 3" body lift will require more work and you will also see the frame from the sides, gaps in the wheels wells, and a low riding hitch. With 1.5" the hitch doesn't look ridiculous and the exhaust tips are adjustable like mentioned above. You cannot get the tips back to the factory location without going on a steep angle, however. I have AFE 5" black tips on order right now which should look pretty good with the body lift.
Regardless of which body lift you go with, you will need to remove the front and rear bumpers to relocate them. Both will require drilling the frame. The rear bumper requires some grinding to remove some studs. Air tools are a must, IMO.
The 3" body lift requires removing the air box, adding a steering shaft extension, and extending the fuel fill line. You will likely want to have the rear exhaust relocated as well. You will also want gap guards for the wheel wells. IMO, you can also tell that the truck has a body lift with the 3".
Installation wise, after you pull off the front end, adding the spacers is a breeze. Loosen the body bolts, jack the body up, insert the blocks, and move on to the next side. I have the Zone Offroad kit, and full installation instructions with pictures are available on their website. They take you step by step through the process. The majority of your time will be spent relocating the bumpers.
Here are some pics. At the time of the pics, here is what was installed:
Rancho QuickLift Struts (2")
SSC-50 HD Rear Coil Springs
Rancho 9000xl rear shocks
Zone Offroad 1.5" body lift
Note, the exhaust tips have not been adjusted at this point
Since the lift, I have also added the 3/4" poly spacers from TGC and Airlift bags in the coils because the rear end always looked saggy. I don't have pictures of my current set up. Hope this helps.