I think cohabitation is good for a couple. For most people it would help them find out if this person is the person that is right for them. While living together they would get to see how the patterned reacts to different situations either good or bad ones. Also to see if they can handle the finical needs of the home. I believe that you will never know what a person is like until you live with them and see firsthand what they are like all the time, if you can’t make it through just living together your marriage will probably never work. After people marry some things may change but not much from what they seen before the marriage while living with one another.
I would live with my partner but only when I believe we are ready to take on the responsibilities of having a place and being around them all the time. Before I would move in with my pattern I would make sure that we have our finical needs figured out and make sure we have the money to support the home. Also I would make sure that we know each other well enough and are ready to commit to my partner.