Like John mentions, a lot of it depends on the length of the trip. I do the same, but for different reasons. For 3-season weekend trips where im just boiling water for freezer bag cooking, It's always been the caldera keg for me (with esbit). The whole system weighs 3oz for me, which is lighter than any decent sized titanium mug alone. With enough care in packing, there's no reason why it won't survive for the long run. I only limit it to weekend trips on the off chance that I somehow crush/destroy the keg can (highly unlikely IMO). With a 3 day trip, the consequences aren't that dire...but on anything longer, It may be a major set back. So for longer trips, or winter trips, I find myself using aluminum/Ti.
If you aren't thinking long duration trips, than go for the keg. I was able to talk to Rand directly and order the cone itself, since I already had the keg pot, and had no need for the plastic container or alcohol stove. He sold it to me for a very very reasonable price.
If you are worried about BPA, you can always sand the liner out of the keg. And while some may argue that replacing the keg if it ever breaks is a reward, I would venture to say that that's actually debatable given that it is heineken :/