Myself and a few other guys have done some research and had experience with these spindles. If you want the best ride you should get the McG for 16+ wheels. The reason is because all of the 2" drop spindles for 17+ wheels stretch the distance between upper and lower mounting tabs by 1". That causes camber and bump steer issues. I've had stock, mcg 16+, and belltech 17+ spindles lined up on my garage floor to measure the difference. The belltech upper and tierod tab are lowered 1" and the lower is lowered 2" compared to stock. The mcg 16+ has all three tabs lowered 1". The way they get the other inch of drop is by mounting the lower ball joint on top if the lca. The benifit to this spindle is keeping stock geometry and still getting a full 2" drop.
The loss in turning radius can be fixed. Read Matt's thread on how to fix it:
http://www.gmfullsize.com/forum/showthread.php?t=160242
Edit: This crapy paint shows exactly what I'm talking about when I measuerd the drop spindles. This is with all the hubs lined up.
