I also use the lazers now as they are pretty simple when using certain ones for certain applications, but as Len correctly stated they do not always tell the true tale of the tape in all instances or are the "be-all, end-all" of tuning. You can determine cam lean, limb twist, and centershot without them--- sometimes easier in fact if you have your "method" down---techs have been doing that long before the lazers came to be.
Good shooting, Pinwheel 12