I think it really makes the POV fighting feel very "crazy" and makes the person really look like they are full of rage, I can almost feel it while watching.
What other kinds of little touches did the directors/creators/producers add to make TOS stand out at the time?
The cinematography was treated -- in terms of AMOUNT of light -- almost as Black&White, something Finnerman learned from old-time pros. What you get when you really push things is what he called a half-tone, where you see detail in the faces even though that part isn't bathed in light. On really good Kirk closeups, you can see the big backlight, the silhouetted foreground and an edge of detail that makes for a very rich image.
Finnerman talks about this in interviews in CINEMAGIC and CINEFANTASTIQUE magazine and I think maybe in STAR TREK INTERVIEWS book too.
Personally, I just love the amount of black in the frame at times in BALANCE OF TERROR and DAY OF THE DOVE, especially the latter during the 'ship out, freak!' scene.
Frankly, I'm bored by the see-everything look we've drowned in since they started making filmstocks resemble video more and more, and now digital has just begun to look like film to a slight degree, but things still show too much mid-range for my taste. But they're not using as many movie lights, so I guess naturalism is going to be in for the forseeable future.