Seconded. Or, more exactly, I like what was done, but even if the new VFX had merely been mediocre, it would still have been an absolutely crucial improvement.
The original "Doomsday Machine" was completely dependent dramatically on the plausibility of its space combat scenes - even more so than the battle-heavy "Balance of Terror". Unfortunately, the original effects were abysmal; either they represented a bad day for a competent team, or were sign of thorough incompetence. The scenes were completely lacking in depth and the phaser beams were rendered in a childish, coarse manner that significantly distracted from the supposed excitement and menace of the as such interesting space monster.
Now, the new effects also suffer from somewhat silly phaser beams: I absolutely hate the way the beams never focus on anything, but merely drag along the surface of the monster in an inefficient manner, which also happens to be the manner a beam drawn in by a dramatically unconcerned or otherwise lazy VFX artist would do it. But at least the scenes finally have the required depth and 3D motion, restoring credibility to what originally was a smelly brown stain in the TOS record.