Abba_S – I usually get a lot of critical information from references! Granted, I have a lot of experience and know what to ask and how to get information from people. By asking references, I have been saved from going out with and possibly marrying people with very serious problems. It sometimes happens that I am not able to get useful info from the listed references. In those cases, I ask around until I find people to speak to who can give me useful information.
It is critical to check people out before going out! It is basic hishtadlus. There are many stories of people getting married and then divorced because of information they were not told on time. A friend of mine had a friend who nearly got engaged (or maybe was engaged) to someone before she found out he was a child molester. Boruch Hashem, she found out in time before she married him!