I will leave the details to the people who can actually write good movie reviews. I am here to present only my opinion and I did NOT like the movie for the following reasons.
1) It has ridiculed and disrespected the oldest faith - Hinduism to a scale never seen before.
2) It has glorified Pakistan- Enough is enough. I do not want to see any more glorification of a failed terrorist state that is run by 6 different governments that agree on nothing except that they want to destroy India.
Why not a romantic side with a guy from any other country or even Indian state?
3) If it were to be a satire, then why not ridicule every faith equally - why the gigantic bias?
4) It is a beaten track. OMG did it already and it was better. OMG did cross the line on many points but still managed to pull the act together. But PK never even attempted to do that.
5) Finally - There is a huge difference between artistic expression and pushing an agenda. This movie is very clearly pushing an agenda.
Belittling ancient traditions, mud slinging on religious gurus, and insulting the temples and Hindu way of worship. Sure they took a few swings at other religions but those scenes lasted only as much as wink and yawn.
One of the dialogues in the movie is "Jo dar jata hai woh mandir jata hai". Having said this and all other statements, I do encourage you to watch the movie and form your own opinion.
That it is a well made movie there is no doubt. Do pay attention and read between the lines.