Ah, but they zing past what you are shooting at so much faster!
Crap. Neat if you want to hear an air rifle with the crack of a sonic boom, but completly useless otherwise. When dealing with the higher power airguns, I'll take mass and accuracy over speed anyday.
I get through and thoughs on rabbits with my Cabelas Outfitter pellet gun shooting regular lead pellets at ~850fps