I live at the beach, it's where I have done most of my "offroading". It's depends on what the weather is like, and how moist and compacted the sand is, but after you get used to it... it's easy running either way.
Before the police started constantly patrolling the north end at Carolina Beach, we used to go down there and drag race our trucks all the time in the sand. Kind of boring now though, with the speed limits and the constant threats of getting ticketed for careless and reckless driving. Let a couple of dumbasses endo their Jeeps off a dune or run over a sea turtle nest and it ruins it for everyone. I miss that scene a whole lot. It was a weekly party(all weekend) on the beach. Big camp fire at night, lots of booze, loud music, hot half-dressed women running around everywhere... Now it's mostly populated with fisherman who expect you to drive by them at 5mph and they act like throwing a rooster tail is worse than if you had just walked up and punched them in the nose.