LWRC would be a good option to POF if money isn't the issue.
All said and told when you start looking at a SHTF scenario the considerations change. If you don't have to relocate then over all weapons weight doesn't much matter, nor will things like batteries etc... that of course is working on the assumption that you are even moderately supplied.
If you have to move, weight immediately becomes a significant issue. If you spent any time in the military and near any unit that was considered "Light" you'll understand immediately. I unfortunately spent 15 months in a Air Assault Unit that did a lot more cross country on foot than in the birds. As a result I learned that even the essentials end up weighing a lot (in my case, with a full combat ammo load that approached 100+ LBS between the ruck and personal carry). Now during that time I lugged around a M16A2 w/ M203.. a heavy pig by anyone's standards... so I've tried to ensure that at least one of my AR's is fairly light weight.
I'd love to have a piston upper such as a POF or LWRC, but I realize that most likely I would grab my Franken AR that is a good couple of pounds lighter than any other I have.
I'm looking forward to serious range reports from you guys that are either getting or have LWRC weapons. And for those with worries about parts.. for very small extra expense, the primary break points of the BGC, LPK parts and or even the Piston system.. can all be had as your own spares. But again I have always advocated having more than 1 weapon.. Murphy is an ever present bastard and he's caught me enough times in the past that I try to minimize his options where I can
So I'm going to agree that there is some serious logic to be had in the point that having a weapon that is fairly close to what would in theory be available from local sources is a solid plan.
I still say stay away from batteries, heavy accessories and will add a strong agreement to getting and storing as much ammo as you reasonably can. Have a plan to cache big chunks of it if you have to relocate.. Hell... just have a fricken plan. If nothing else Katrina should have been a serious wake-up call to those of us who have zero faith in our Governments ability to help when it really is needed the most.