I love the original episode, but the poor special effects (especially the close-up of the Constellation entering the Planet Killer near the ending) take me out of the story. I feel the re-mastering is an improvement and only serves to assist the character-driven storyline.
To me it is quite the opposite. The shiny new 21st century CGI effects clash so much with everything around them that it yanks me right out of the story because it is so jarring.
But honestly, if people get pulled out of stories by shoddy FX, then perhaps they shouldn't be watching 40 year old low budget SciFi TV shows.
And a true "remastering"--which I would have welcomed-- wouldn't have added any new elements to the episodes, merely enhanced what was already there.
The Sci-Fi Channel already did that kind of "remaster" back in the 90's.
I like the CBS-D remaster, but I think the FX could have been more TOS looking -- or rather more 60's looking -- like Daren Dochterman's attempt at Doomsday Machine. I still would have added/changed things though here and there...