At 600-700mm, this would be a dandy shot too, but maybe with the clarity you are looking for. You sure found some very attractive little birds to capture this day.
I never heard of anyone laying in a beanbag and shooting photos Count B. If the shots aren't any good you can feed the beans to the birds. This is a good one.
Those beanbags come in handy for all sorts of things. I like the ones that are filled with Boston Baked Beans. When I'm done taking pictures, I eat the beans. Yummy! Pretty nice shot again with your new toy.