"...The arrangement of grounding connections shall be such that the disconnection or removal of a receptacle, fixture, or other device fed from the box will not interfere with or interrupt the grounding continuity."
Any reasonably experienced "handyman" knows that it is easier to remove a receptacle (if it is pigtailed) by removing the wirenuts than it is to wrestle the wrapped wire off of the terminal. In replacing a receptacle, said handyman may choose to remove the greenie in lieu of unscrewing the ground screw. With barrel crimps, this proves to be rather difficult.
Perhaps this is very arguable, I'm not really saying it is code, but I feel that barrel crimps do offer many advantages in EGC situations.
[This message has been edited by sparky66wv (edited 06-21-2001).]
-Virgil Residential/Commercial Inspector 5 Star Inspections Member IAEI