How many times should you listen to a cd before submitting a review?

How many times. After listening to the new U2 album I thought it was horrible after one listen. 8 listens later I love it, It is a real grower. I am thinking of doing CD reviews for a magazine soon and I just what some feedback on how many times you should listen to write an accurate review. When I dont know if I like a record or not I simply describe "The song magnificent starts with an intriguing ensemble before warming to The Edge and U2's characteristic delay ridden sound"