well I'm not sure how much my opinion counts seeing as I have only been married for going on 5 months but we have been together for over 6 years.
The problem that I see with a lot of marriages is that they happen way too soon. This whole getting married after being together for a year is ridiculous. Sure, there are some that have done this and have a happy marriage but there are many many more that fail. I don't care how much you think you know a person during that brief time, you never know everything. It's even worse with people who do not live together first. To not live with your partner before marriage is a recipe for disaster.
Some will say: "well my parents or grandparents never lived together before they were married because it was taboo back then". Well back then, divorce was very very uncommon and looked down upon so they would just live with the fact that they don't love one another and it was done for the sake of the kids. They end up sleeping in separate beds, never going out together, and only really being together when it involved the kids.
I say you should live with a person for a minimum of a few years before even thinking about marriage. Why not invest that little extra time to make sure all your ducks are in a row? For some reason, people think they must get married asap. I'm not sure if they are holding onto some childhood dream of getting married and making babies or what. This immature belief is what bites them in the ass later on.
I also think that if you are looking for someone to marry, you're gonna be let down. It's not something that can be hunted down. My wife's friend already has her wedding dress, wedding location, etc picked out and she doesn't even have a boyfriend. This kind of desperate, anatomical ticking clock mentality is what drives most guys and girls away or ends up in marriage only to last a few months and ends even worse than if you wouldn't have met the person in the first place.
To end my rambling, if you can't see you and your partner being friends, don't consider them marriage material. After all, your partner will be your best and closest friend until the day you die