if you did 2 week primary, 3 secondary. Your beer would clarify more. To be honest Ive left it in for 3 -4 weeks and didnt know a significant difference. 3-4 weeks was more due to being busy. I find the transfer sometimes stirs things up. So I would go secondary longer. if you leave in primary for 3 weeks, just goto 4 and bottle/keg at that point. I did a Hefe in primary for 4 weeks and went straight to bottle. it worked fine. I thinks it personal preference really. I only have 1 primary/1 secondary. So, I rack more to free up the primary.