If traveling extensively or especially flying go with a plastic case. Plastic absorbs shock much better than aluminum or metal, is generally lighter and with a water tight seal will normally float. You also want easy access if flying as the TSA will want to check it with you there (unlock inspect and re-lock). Watch out for anything that sticks out, paddle locks hinges etc. . . I am a big fan of the SKB plastic cases and buy a double it will come in handy for other stuff such as spotting scopes, cleaning rods, tripods etc.... You can buy foam and make several cut outs depending upon your hunting/locational needs. Pelicans are nice cases as well. You are going to hear a bunch of BS about hiding it in music case etc. . . you must declare it so everyone knows what it is. I have traveled all over Africa, North and South America and never had an issue. My old SKB is battered but logged more frequently flyer miles than most salesman.
OH, and wheels are very handy as well as webbing to add other stuff in tow.