Thanks for posting this info! I recently got Thor an Argo airline-approved bag (smallest size) and I really like it. It's the only bag I've seen that Thor is not swimming in. It's the perfect size. I don't know how discreet it is since it has a huge orange logo on it, and it's not really designed to hide the fact that it's a dog carrier. Anyway, I'm looking forward to flying somewhere with Thor! I think he'd like Mexico or Hawaii. Or maybe a little poker in Vegas.
I have another bag (not sure of the brand) that no one would ever guess is a dog carrier. Even when I've showed people the bag, they can't tell if Thor is in it or not. That's my grocery / shoe store bag. The only thing is that the straps sort of slide off my shoulder, which is annoying.
Anyway, I'll definitely check out the links you posted, thanks again.