My fiance and I have dated since 2006 and never lived together. The one time I almost spent the night at his house was when he had suffered a head injury, just got back from the ER, and needed to be checked on regularly through the night to make sure he was only sleeping and had not become unconscious again. His grandmother was able to stay with him that night though, so I didn't have to. If I had to though, I highly doubt it would have been considered "staying the night" in that sense. He would be the one sleeping, I would be the one in the other room chugging coffee and watching late night infomercials to stay awake so I could check on him periodically to make sure he is responsive. That's no one's idea of a romantic night.
I absolutely believe that it is for the best that he and I have never lived together. He and I have built our relationship on who we are as people, not on what the other can offer sexually. The fact that our entire relationship leading up to marriage is built on ourselves as people and not on our bodies means we REALLY know the other person and can keep the focus on what really matters. Has it been hard? Sure. But it's worth it.