"***Posting this review on both bars***
I bought both a Mainstay and a Datrex 2400 calorie bar to try out the flavor of each to determine which one I would end up wanting to use in my ditch kits. From some other reviews I thought they might both be the same, they're not. Here's a short review.
Datrex bars are broken up in to 12 individually sealed 200 calorie cakes. They have a taste not unlike stale graham crackers. They can be somewhat crumbly, though. I grabbed a few while at a convention and they broke in my pocket. They were still edible, but were falling apart.
Mainstay bars are one big bar sectioned into six 400 calorie blocks. They're thicker than the Datrex cakes. These have a slight lemon sugar cookie taste, but its very mild. They're less crumbly than the Datrex bars, however, you CANNOT reseal the package once its open. (Unless I'm retarded and missed something.)
In the end, I think Datrex bars are better for ditch kits, car kits, or anywhere you might have multiple people around. They're very easy to divide up. Mainstay bars seem less prone to falling apart and making a mess, so would probably do well in shelter in place kits. The taste of both is pleasant (to me) so you'll probably just have to find your preference there. I'll probably end up getting both for variety.
On a side note: It may just isolated to my insane cat, but both bars seem to drive her mad. She was trying very hard to get to them when I tried them. "
Pros:
Long Shelf-Life, Easily Portable, High Quality, Low Price, Light Weight, Delicious Taste, Small Size, High Nutrition, High Calories
Cons:
Small Variety