Hi Wayne,
You're going to have to do some research when you're considering the purchase of lenses. Personally I hate to come right out and say a lens is good or bad because
one, I may not have any experience with it,
two, I may have had experience but with a bad/good copy which may not match your results,
three, the model indicated may have a close relative (the 70-300 for example) and we may not be talking apples and apples. That said the reviews at fred miranda didn't sound promising for the 28-70 :-/. The 70-300 quality will depend on which one we're talking about, see this
article here. Also, when evaluating the input of reviews make sure you know your source and whether they're impartial (or trying to sell something).
