The Public version is just for surfing. Its seems reasonable to me that the free Public version is lower security (= easier to maintain, give away free, able to be used by more folks, simplier, a plaything, the alpha-version, try-it-first-here-before-lockdown, etc.) and the Remote Access version would have far more advanced security features. The pages hints at just that, even saying its only given out as individualized custom builds.
Given that DoD laptops are some of the most locked down computers out there AND the DoD is very defensive about its networks AND the Government is a vast bureacracy, it would suggest that this 'new kid on the block' has to be far superior to the existing solutions get that high a level of approval - the DoD CIO approved it for emergency use!