My healthy relationships have started out on a friendship level. I'm pretty sure than when blinded by NRE I don't really see the whole person all that clearly and end up getting swept up into a relationship that isn't right for me. With friends you already know you like each other and you have something solid to build on. Rushing into becoming lovers before you know each other well is kind of a crap shoot as to whether it will last or not.
Everything will be ok in the end. If it's not ok it's not the end.