I have a gun case that has literally flown more miles than most people I know. I will only use all aluminum cases for travel. Had a rifle and shotgun in aluminum case get hung up in Europe for several months one time and needed a case to go on another hunt. I bought another just likt the first one and got on a plane.
I have seen "indestructable" plastic cases destruct in dramatic fashion. Many people never fly with a gun, and those who do usually only make a couple of trips in their life time. The folks I know who fly on a regualr basis also use 100% aluminum cases.
I use Kalispel cases. Not the cheapest, or lightest, but worth every penny and pound.
http://www.kalispelcaseline.com/Default1.aspI also ship expensive guns many times a year, as do many of my friends. We have all seen rifles in good plastic cases break all too often. I have not seen one broken when shipped in a full aluminum case.
Oak and Leather looks cool, no doubt about it. But if you are not storing the guns in the cases where you and others can view the oak and leather, then I see little value in it. If you are interested in protecting the gun, then you can't beat a totally aluminum case.