I didn't read the other messages, but....I also have the 104 hillrom vest. I always travel with it when I leave town.
I just put the vest/machine and tubes in a travel bag with wheels and it fits all in one along with my pari pro neb machine. The bag is heavy, but it works and does fit in the overhead compartment on the plane. Another trick I've started to do since that bag is so darn heavy and awkward is before everyone starts loading, I go to the boarding desk for that flight and ask if I can board early with the handicapped/kids section. They ask why and I say b/c I have heavy medical equipment that is tough for me to load, and that it takes time to deal with. They give me a pass so I can board early. This can take a lot of stress off my mind especially when I'm not feeling so spify!!!
I've heard (I believe from Hillrom) that the vest is not suppose to get check on the plane b/c the pressure or something can disrupt the computer chip inside the vest causing it to break. So you have to take it on the plane with you for 2 reasons: 1.) so it's never misrouted and you're without your treatment, and 2.) b/c it could break if it's put underneath.
Second thing you should know (someone probably already mentioned it above) is they have to stop you at security to check it out with the bomb cloth detectors. This just takes extra time for you to deal with, but always gets through no problem. Have a doctors note with you just in case. I keep my note in the side pocket of that bag so it's always there.
Good luck and have fun!