This may not be the right forum...
...but I just picked up a used Canon 100-400L at a good price and used it for the first time the other day while my Golden Retriever was doing what she does best. I like the extra reach over the 70-300L. Need to get more adept at the push-pull mechanism. But overall, I'm satisfied with the initial results.
|Sit on rainbow by frapeace|
|Icelandic landscape by BoDrey|
from Best Landscape of the Week 1