I have both (Stag 2T & LWRC M6), and if I had to grab a gun and head for the hills, it would be my DI. My piston rifle is heavy and, while it has never jammed on me, neither has my Stag. I usually shoot free standing, prone, and kneeling since it seems to be the most realistic way to practice, and the heavy front end of the LWRC wears on you quickly. I think if anything, buy a good DI and send the bolt & BCG in to be NP3'd so you can clean her up faster.
The more I shoot and think about a realistic bug-out plan, the more I see myself taking my 30-30. Much more simple and easy to handle. Think about it: if your bug-out plan sees you shooting the gun more than being on the move, you should probably come up with a better plan! Even if you think this will just be a range toy, you should take the whole bug-out notion into consideration if it's your only long gun. If not, then no worries. Range & HD roles will be fulfilled just fine with a DI AR, just practice with it until you know her inside & out.