There are four distinct products in production (public, firewall, ghe v1 and ghe v2). I've explored the internals between all of the minor and major enterprise releases over a beer or two on a lazy afternoon. The initial product was a separate spin-off and there was definitely product convergence at the ghe v2 stage which appears to be based off public. My best uninformed, informed guess as of v2 they are now on the same branch, potentially using feature flags to enable/disable behavior to reduce maintenance/support overhead. Extremely interesting stuff can be found at the pre-install and immediate post-install stage (use standard forensics tools + granular vmware snapshots to produce diffs) that's all I will say on the topic however.