This is the most discussed topic on here, it has been readily covered. I suggest you read THIS thread, it's become the "uber discussion" on this topic thread. Every discussion, question, answer, citation, etch is in that thread....
To Secondary or Not? John Palmer and Jamil Zainasheff Weigh In .
Many of us leave our beer in primary for a month minimum then bottle.....We find out beers to be clearer and better tasting.
I suggest you read that thread, and experiment for yourself,
and make up your own mind.
There's thousands of threads where folks have ventured their opinions, and argued incessantly, but it ultimately comes down to what works for you......