Something to consider...
THX-1138 had more than just a clean-up job done to it for its limited theatrical and DVD release that is upcoming. It spent a decent amount of time at the Ranch and George revisited it with new scenes and special f/x.
Considering the darker and harsher tone of this film, it is interesting to note that this was all worked on, and fresh in the brain of George right before and during development on Ep 3.