JPS,

That really depends on the application. Yes, there will be a difference in speed as well as a 3 inch or so difference in axle to axle length and an approximate half inch difference in brace height. Differences in noise and vibration are negligible.

I do feel that the XT2000 limbs are the best made limbs today but, for most archers, they are somewhat of an overkill. Most of the guys that I know only shoot a few times a year and normally shoot arrows that weigh in excess of 6 or 7 grains per pound...which means that the bow doesn't take that much abuse. On the other hand, if the person in question is going to be shooting the bow on a weekly basis at a low grains per pound ratio and with either a heavy draw weight or long draw length then I would definitely suggest the XT2000 limbs as they are built to take more of a beating.

Hope this helps.