Blue/Bill: I'd have to agree with the reviewer in your link. The 70-200 f/4L is a much better choice than the 70-300 in this price range.
The 70-200 f/4L is sharper but lacks IS so that might be a bit of a wash depending on your application. The 70-300 has extra reach but it's right in the 200-300mm range where the IQ starts to deteriorate on this lens. Build quality is much better on the L lens.
The fact that the 70-300 is not parfocal and has a rotating front element is a deal-breaker IMO. That makes using a graduated ND or polarizing filter very awkward at best if not downright frustrating.
I will refrain from making CC on your pics as I don't have a jacket to take off at the moment.
