It would definitely be full.... at least when I checked it :-)

As far as pressures, I'd be packing it at 10psi at about 5300 feet, if ambient air pressure went down, that would actually increase the pressure of the contents of the keg, and when I land at sea level the contents would be approximately 7.8psi, and the container is rated to roughly 110psi. I don't think that will cause any problems...

Thanks for the link, but reading a lot of the posts, yes people have been affected, but at the same time I've packed LOT's of wine and beer (bottles, but never kegs) across the country in and out of LAX, SFO, and many others. Nevertheless people have been affected in the past, so I appreciate the info.