I agree with colomojo - south of town is great because you are close enough to get to town to eat, shop, keep the kids occupied, etc but far enough away that the beach seems very private and there's not much traffic (if any at all at the home you are looking at south of the dump). We also rent a cart, as it gives us the freedom to come and go as we please.
I, personally, would like the seclusion of being 6 miles north, but my kids would probably disagree after a day or two.
Keep in mind, if you are doing any excursions, the tour operators offer to pick you up (at least they do south of town, and I would think north of town would be the same).