The Pelican 1510 isn't really built for either IMHO. It's too big for carry-on and isn't built well enough to function as a checked bag.
Every airline has very detailed information about size and weight restrictions of carry-ons, and you'd be doing yourself a huge favor to stay as small as you can. Those overhead compartments can be tiny. If it were me, I wouldn't go with a hard shell case as a carry-on. You need a little bit of "give" in order to be able to stuff your bag to make sure it fits or you risk it being checked...and then you're really screwed.
You can fit a lot of gear in soft-sided backpacks and sling packs. That would definitely be my choice over this Pelican case.
As luggage, keep in mind that you'll be landing in a foreign country and you can be sure that the baggage handlers there are going to give even less of a crap than the ones here in the states. If you have to go this route, buy a tank of a case.
The very next thing you should do is purchase an Inland Marine insurance policy and make certain that you're covered for trips abroad. That will protect you better than any case.