Canon zooms

[Coxlaw]

I am trying to decide between canon ef 70-300 usm and the canon ef 70-300 using the dc motor instead of the usm. The price difference is around $300 and I am wondering if the esm motor makes a real difference. Any ideas?

[MrJones]

I don't have the 70-300 but I can tell you that the USM engine makes a world of difference!
I have the 50mm f/1.8 which doesn't have the USM engine and I can't wait till I get my hands on the f/1.4 version, just because of the focus speed of the USM.
I'll never buy a non-USM lens ever again!

[ishootRAW]

Dont worry about the motor, Yah it is slow, but you can live with that. The more import thing is the fact then lens is 30 years old, Its not sharp at all.