IMO long engagements are bad and my family does not believe in them. They do simple nikah and then give the couple a few months to plan the wedding if they wish.
What happens during the engagement period is the couple gets restless. This is simply my opinion so dont count on it being true, lol. After both families agree on a union and everyone has the green light, there should be a brief period and then the couple should get married. They have to start their lives together to take their relationship to the next level. If they dont get married soon, their relationship kind of stays suspended...until you make a move either forward or backward.
Couldn't have put it better myself. Very wise words.
People! Listen to her! ^