In nearly all of my long term relationships, we had sex in one form or another on the first date. If that is what you both want, why wait? Because of what "you think" he or she will think of you? I have never disrespected a sex partner for not waiting.
As far at the person who will just "hit it and quit it" CinnamonDreams, that person is just foolish. Sex gets better when you become familiar with what your partner wants and likes.