jrjr99, like the heron shot.
Graham, you're right. I just feel short changed at ISO 12800 so the flash is a step up, regardless of the negatives. However, if the result is not appreciated by whomever, that takes away the enjoyment. In time I'll be able to gauge that.
Now, if I could afford another 600 EX-RT, yes I could position it to catch return visitors to the area I'm shooting towards, although that's a little challenging, unlike the on-camera flash. It's a clump of trees that many birds love and close enough to get decent shots, like 10 - 20 feet. I also have a couple props that are attracting some customers and they are closer and would be easy to roughly aim a second flash at.