I think the difference other than price,is the XT2000 limbs are suppose to give you more speed and they're suppose to last longer,more durable(spl?).Frank might be able to answer you better then me.I have the ZR200 limbs on my Vortec and my new Havoctec.I'm getting about 274 fps with my Vortec set at 65#draw weight and 75% letoff with a Beman ICS 340 hunter arrow at 28 1/2"long and a 100 grain feildpoint.