Perfectionists spend more time cooking, writing or even painting, but what they eventually finish is noticeably better than something created by other Sims. Perfectionists accept nothing shy of perfection.
Sim does most things better than other Sims, but sometimes it just takes a bit longer...
Sim can paint higher quality paintings, prepare higher quality food, write better novels and do homework better [confirmation needed].
Perfectionists always do neat actions automatically, such as making their beds after waking up or cleaning their dirty dishes after eating. For this reason, Perfectionist is like Neat, but with added benefits at the cost of time.