We have flown 2 of our PWDS in the cargo hold (each one time). I don't think we'd do it again unless we really had to. Our second PWD flew from Toronto to California and back again. Ever since she has been fearful of loud noises like thunder etc, I guess because of the noise of flying. We found it very stressful as well - we just didn't feel the way the process is set up is in favour of the dog (or owner). So yeah, no more flying for us unless essential!