Balance of Terror: Establishing Shot

This opening shot of the Enterprise changes the angle of approach and adds a motion blur effect.

This opening shot of the Enterprise changes the angle of approach and adds a motion blur effect.

The Enterprise zooms by during the opening titles.

Geologic features are visible on a new computer-generated planet as the Enterprise flies by during the opening credits

Surprisingly, no changes to the viewscreen display. At the very least, I would have expected Romii (Rom II?) to be changed to Remus.
Captain Kirk even mentions Remus by name in his log entry at the beginning of the episode.

The Enterprise pursues the Romulans. The CG ship in this sequence looks like something out of a bad video game.