I played the demo and enjoyed it, but not enough to buy the game. A friend did buy it though, and he's having a good time with it.
"I got captured by rednecks and they made me their gimp!" - Nice homage to Pulp Fiction.
On the whole I think people have been fairly harsh in their treatment of the game. Yes the load times are annoying, but in any particular load zone you have a fairly large level with detailed, populated interiors and an open, hilly exterior that meets my standard of "good enough to permit suspension of disbelief" detail. The AI's interaction with each other and some of the scripted sequences are entertaining and dare I say polished.
Moreover, you can finish the game without ever firing a bullet. The implications of that element alone puts a smile on my face - if you think the game is #%$@ed up, then maybe you should just take a closer look at how you assume you are supposed to play it. If I had a category in my budget for "support worthy efforts at unconventional/irreverant game design", the folks at Running with Scissors would be top on the list for my money. As it is, I picked up Vice City for PC from my "enjoy myself when not at work" budget and that'll hold me for a while.
That said, I would love to see a Postal 3 made with the Half Life 2 engine...