Especially read the posts made by Greg Dupree regarding this point. I won't go into all the details, but basically during the onset of detonation on a boosted engine, pulling timing is not always the best thing to do. Try to learn a thing or two about combustion dynamics on your own. It is far from correct to just automatically state "X is better then Y because this one pulls timing and the other one doesn't". Because that is far from the best method for all cases.