the spacers just raise the bars up, but the heli-bars not only raise but move back toward the tank. they also have a slight bit more outward angle. this keeps the wrists straighter. It will depend on your reach, taller guys/gals(don't want to offend)probably don't need much movement back toward the tank. I'm 5'8" and I find just pulling my hands back about 1.5 inches really helps in riding comfort. The heli-bars are my next mod. If I find that is still not enough, I like long rides, then I might add a spacer and roll the bars a little more.