I personally think TOS-R "The Doomsday Machine" is one of the worst of the TOS-R episodes. In my opinion at least the original effects looked better than the cartoons that replaced them. The texture on the doomsday machine itself was just pathetic. Don't even get me started on the interior of the machine or the super cartoon looking force beam that it emitted. It really renders one of my favorite TOS episodes unwatchable for me. To me the remastered effects were nothing more than a gimmick but I'm glad to hear that some like them.
Nah, the repetitive stock footage, very poor matting, loss of quality from analog triple head printing, bad lighting, terrible Machine model, improper scale and composition is actually a demo reel in one place for the poor FX of TOS. Even the worst TOS-R CGI would be superior in every way. They also took great care to map out the battle and choose the proper angles and relative positions of the ships in the remastered version. All come together to produce a stellar reworking in the form of a TOS era episode.