This is my personal opinion applied to my own personal life.
My parents did not live together before marriage, and they've been happily married for over fifty years.
Living together before marriage doesn't seem to reduce the divorce rate.
Personally, I lived with my husband for just a few weeks before we were married - and it had more to do with a lease situation than anything else. We were engaged with a wedding date. We dated about a year before getting married. We have been very happily married for six years now.
Oh and did I mention that for most of those weeks we lived together before marriage, he was overseas? So it hardly even counts!
I personally would not live with anyone prior to marriage unless we were officially engaged with a wedding date that was clearly defined. But - I am a very monogamous person, I enjoy marriage, and hell, if I am going to move in and set up house, I'm not going through all that if marriage is not in the plans.
Also, I like the independence of my own place and my own life if I'm not at the point in a relationship to be engaged. Not engaged or married? I have wider parameters and those parameters include my own physical and emotional space and solitary time.
But hey, that's just me.