Premarital ....to have or not to have?

We've all heard it before, "why buy the cow, when you can get the milk for free". It's crude comparison but as with most sayings from the past, i believe there is some truth to it. I am not looking for answers based on morality or religious convictions, but rather rather candid subjective opinions. I personally think that is an important part of a healthy marriage and in keeping the union strong. So, I can't fathom how you could blindly marry someone without knowing how they are in bed and if everything is agreeable anatomically included. Its like a crapshoot, it really could go either way, and you're blissfully satisfied or dreadfully disappointed, but then you are already married. Then off-course there is the scenario where a man has already had you for a period of time and needs to decide if he wants to spend the rest of his life with you and make good on all his promises of love or move on to sample what else is out there. So it seems either way.....it's a crapshoot. Which do you think is best. To have or not to have?