Ah, not really know them in a day, but in one day of talking, people say things...things that might make you think....ick. There are so many things you could talk about...politics, religion, families, so much. I think enough to either make you want (or not want) to come back for more.
Oh yea, the adversity thing. That's heavy.
My friends and I always had a rule of thumb. If a couple can make if for 9 months (long enough to let you hair down, and most like periods of some adversity), and you still want to be with each other, then you have a shot. It's not clear sailing, but it a good beginning foundation.