I'm of two minds on it. Part of me would have preferred they replicate the original effects shots to keep the original feel while still making them appropriate for the HD transfers. I'm not all that thrilled with the live action changes (the phaser firing in the corridors of Wink of an Eye for example), but the matte painting updates were very cool. For some reason, I also don't really like the super duper close ups of the Enterprise as it flies across the screen (See Return of the Archons). I prefer to see the whole ship.
On the other hand, going a little further gave us a sequence at the end of Tomorrow is Yesterday that not only clarified the slingshot effect, it became an exciting sequence as well.
Blood spattering? I don't think we need that in Star Trek ever. Her death by explosion was effective enough as is. Where is the line, if you go that far? Do they CGI in a boner every time Kirk sees a hot chick?