[badpickev]

from my usage and testing. optically speaking from best to worst

70-300 VR
70-300 ED
70-300 APO - sigma
70-300 dl - sigma
70-300 - tamron
70-300 G
70-300 tokina

anything not listed here is usually worse than the ones listed the last four are all pretty close to each other to really not matter much. they all are what one would call kit lenses

so i always tell people if you can afford the vr get it.
the sigma apo is really close to the nikon ed, but i have seen just enough of a edge to place the ed about it.