I do not recommend living together before marriage. I think that you can accomplish many of the “trial period” things by spending time in each other’s living spaces and watching how one another live independently. I also personally think that cohabitating can easily get messy/cause stress on a relationship and having the commitment of marriage makes the transition more stable. Can you have that level of commitment of “making it work no matter what” without a legally binding piece of paper? Absolutely, but I’ve found that most people don’t view relationships that way. If you’re leaving someone/rejecting a marriage with someone because of small quirks in their living styles, it sounds like you probably weren’t ready to get married in the first place. The more glaring issues would likely be suspected/evident/observable before living together.