The only reasons people remember 1997's Mimic is because of the trailer shot of Mira Sorvino being swept up by a giant flying bug and it was the first English-language film (and second feature overall after Chronos) by director Guillermo del Toro, who has gone on to notoriety for the Hellboy series and Pan's Labyrinth as well as the upcoming giant-robots-vs-giant-monsters flick Pacific Rim. That's pretty much it and it's not much.
The plot is as thin as you can get: A roach-borne disease is killing the children of New York City, so to eradicate the roaches etymologist Mira Sorvino genetically-engineers a special "Judas Breed" super roach using termite and other bug DNA that will exude an enzyme that will kill the roaches. It's a smashing success and everyone lives happily ever after. The end.
Three years later, something weird is afoot (or more accurately acrawl) as a giant something drags a Skid Row priest to his doom and weird bugs start coming to Sorvino's notice. Seeking the source of the bugs, she and her CDC investigator husband and a subway cop head down into the tunnels, eventually finding out that the bugs have been very busy and gotten VERY large. Frantic battles for survival ensue.
I haven't seen Mimic since it came out in theaters and I couldn't remember what was going on or what was different about this "Director's Cut." Hunting down a comparison online, it appears to be not that much; mostly superfluous stuff involving Sorvino trying to get pregnant that's easily omitted. In the one extra I watched, an interview with del Toro, he explains what he wanted the original ending to be and while it sounds creepy, it doesn't help the overall fact that nothing is explained as to how the heck bugs would mimic people.
Somewhat creepy and moody, but mostly murky and icky, Mimic may've spawned a couple of direct-to-video sequels, but not many imitators.
Score: 5/10. Rent it (since it's not going to be on cable).