Just got a 350d, looking for a good intro zoom lens:

Thinking about either:
Sigma 70-300 APO DG
or
Canon EF 75-300mm f/4-5.6 III USM

They are both around the same price, the Sigma is a little more. Was wondering if anyone has used both and has a definite opinion that one is better than the other (the reviews are all over the place) - looking to take (what else) action/wildlife shots in good light. Planning on shooting at 300 alot. And yes, I would get an L series if I could afford it.

Anything would be helpful.

Thanks

Also - if anyone is looking to sell either of these, PM me...