Thank you so much for all the input. I'm ok with manual focus - I use manual focus for all my shots. My flight shots are my best but then a 300mm zoom is light compared to a prime. And flight formations at least create an interesting image even if you can't necessarily see that you're looking at pelicans.
I've bookmarked your site so I can give it a decent look through after I've had some sleep.
Thank you again for all the input.