All depends on your purpose and your prevailing WEATHER conditions. I have great difficulty with the stock five spoke aluminum where I run. They tend to build up inside worse with mud and frozen crud in the winter running for me. Before I put 1" spacers on the rear I had lots of trouble with destruction of brake slide pin boots which in turn led to rusted and seized calipers and brake troubles. Since adding the spacers which also make the front and rear track in the same path the wheels are spaced out far enough to have build-up clear the boots saving many headaches. My .02 worth.
2001 CC LS, pewter, stock, 4.3,Wait4meperformance, CFM throttle blade, Helix throttle body spacer, 4spd auto, 3button electric 4x4 shift, heavy duty factory suspension, Bilsteins, 1" rear wheel spacers, skid plates.