As you may notice when you view one of these meals on Amazon, there will typically be options for either a pouch or a Pro-Pak. On the surface, the difference seems minimal so that leads a lot of consumers to ask this very question. For the most part, the Pro-Pack and the standard pouches offer the same value but the primary difference is the former is vacuum sealed to prevent any expansion (especially at higher altitudes).
However, the slight tradeoff is they will generally have less food than the standard pouches. Even so, though, they still have the same 30-year shelf life that the pouches have.