Crystal has flown alot and you never heard a peep out of her. I was never allowed to open her carrier or to make people aware that a dog was on the plane since so many have allergies.
Every dog is different but if you plan to be on the go alot , I for one think they are much happier if it's a week or so to be in their own home with a sitter who is certified by a 'sitter assoc' like someone mentioned here. Good Luck.