Okay, now I've seen Balance of Terror. Unfortnately, I didn't order toe HD channel, so I saw it ion regualr TV, and for some unknown reason, that particlar channel does'nt cpoome in crystal clear anymore. I don't know if it is signal loss or RPG from something else (will have to experiement for next week).
The changes I noticed were mostly the CG ships, and weapons fire. Plus I think one or two suble enchancements elsehwere (I want to check with my DVD version, epseically the scene with Outpost 4, to see if they added a bit more sparking to the damage effects).
Yes, overall the effect was very low key, but I think there is really only so much that they can change things. The Enterprise still has to look like the same ship we've known for 40 years or the fans would balk. Same for the Romulan and Klingon designs.
TOS also didn't use much for special effect shots by modern standards (it set records in its day), so about 90-95%of all the episodes are going to look about the same, since most ship shots were failr short, mostly the establishing shots during the captain's log voice overs after commerical breaks.
"Balance of Terror" really only uses a few shot effects, so it probably can't look too differernt. I suppose they could spice up some of the screens, epecially the background ones on the bridge.
I was surprise that they stuck with the "pulse phaser" effect though. Especially as this was the only time it was used (photorps didn't show up yet).
I suspect the more dramtic effects will be in the episodes that take longer to rework. So far we are getting the ones with minimal effects. I am curious how some of the alien planets will look (maybe tossing in a few alien animals, or a bird or two flying on eht e"backdrop" sky?).