for fast, convenient and private eating, nothing beats the MRE. Pull over on the side of the road, find a discrete spot, chow down.

The two can thing works kind of. But that's a little bit dependent on warming times. Very economical though. I notice that a lot of new stew cans come with pop top lids now but they are pretty shitty to eat cold. Cold MRE, not so bad. Hence everybody who eats them regularly has spare MRE heaters around. I also never cook during an operation and carry enough fat that if I skip a meal it's no big deal. I notice that dehydration does not hit me as hard either. All that mess kit and cooking stuff never goes far from the vehicle and if it does, then that's just to base camp.

The big Berkey is strictly a cabin or base camp item. Kind of awkward to put in the camper where shelf space is at a premium but I guess someone could in theory justify it. What I am trying to rig up is a battery powered pump and hose system that uses an inline filter and can then process water for filtration without having to manually operate the system.

All the little manual pumps and straw thingies are ok if you are limited to hiking in and going to be somewhere for a while, but if it is short term, you are unlikely to get that far from the vehicle, so that stuff ought to stay around the vehicle. If it's around the vehicle, the it might as well be DC powered. If it is DC powered, then you can run it off a carry out battery pack of some sort.