Great film - I would pick a knit about the big heist at the end
I always found it unrealistic that Frank calling in the code word to the alarm company after they broke in didn't raise any concerns. Earlier on you see these 2 guys who run the office, they come and go on some sort of schedule and nobody else works there. There are only 2 desks in the place.
I would think the alarm company would find it odd that someone was coming in at that hour. It would have been easy to send a guard or cop to check it out. I know its just a movie and I shouldn't expect realism but the rest of the film stays within the realm of reason.