One of the common ***** points about the MRE's during the Iraq wars was that they took a lot of water to prepare. Probably not an issue in a base camp but a potentially big deal on LRRPs or other situations where one has to carry whatever water one is going to need. In a desert enviornment with uncertain resupply, troops need to keep whatever water they have for drinking and water is heavy. Your typical combat load is about 65lbs-80lbs, not a whole lot of wiggle room for extra water. When the extra water was figured in, the weight load was about the same as canned rations, main advantage to MRE's was they were less bulky.
Dave
Hardly any legs in Iraq when I was there. Most of us were Mechanized. It was so hot that most people ate MRE's once a day. Few of the meals were dehydrated. Most were ready to eat in plastic pouches and mostly eaten cold. I lost 35 Lbs when I was there.