I got the 70-200 f4 for the same reasons you mention. It was a toss up
between this or the Sigma 2.8. I choose name brand, one-stop and $200 difference.
The one-stop loss didn't make that big of a difference for me. I was just looking for a good zoom beyond 70mm. My Tokina 28-70 2.8 is fine below that.
I think my short comings are entirely on me from here on out.
Sorry I don't have any decent examples to show but here is a good site for reviews
Canon lens reivew
Hope this helps Jimmy.
Shot with 70-200 f4.....
Not up for critique mind you
Joe