The "Postal" concept is the most controversial thing in the game world. And you just got to love it.
Anyway this game is awesome on the basics that in this game you can do anything you can't do in the real world and this is a good game to take your anger out on, if you feel rage don't kill anybody in the real world play Postal instead.
The game unfortunaly lack good graphics but it makes up on that with the open range you have to play with and the loading bars are sometimes just annoying.
The crude humor and graphical gore/violence in this game is EXTENSIVE but i think that is what makes Postal great. It's not so much sexual humor as you would think it's mostly violence-based and when Gary Coleman himself goes on the rampage in one part of the game you just got to laugh.
All in all it's a good game with some disturbing content but i can bear with it because I can do whatever I want in this game and i simply like the idea. But still the graphics could be better in the future.
P.S, I don't mind the lack of plot in case you wonder. :)