our most impressive hire was also our biggest headache.
he was really smart, quick, nice, and had an answer for everything.
unfortunately he also couldn't accept things "just working." everything (in his eyes) had to be built to near perfection, and he would go on and on about how various systems needed to change/be re-written.
after we continually refused (as a group) to adopt his suggestions, he left the job for something else.