People ask us this before they book, and they usually ask it the wrong way round: which one is better. Neither. They're the same island, roughly five miles apart, and the honest question is what you want a Tuesday to feel like.
South Beach is the end everyone pictures when they picture Miami Beach. It's dense, it's historic, the Art Deco blocks are genuinely worth seeing, and almost everything is within walking distance of almost everything else. That density is the product. You are never short of somewhere to go, and you are also never quite alone.
North Beach, where we are, is the opposite trade. We're at 7418 Harding Avenue, up near 74th Street. The buildings are low, the blocks are residential, and the sand at Miami Beach Oceanside Park is a few minutes' walk east of our gate. It's wider and emptier than the sand further south, because most visitors never come up this far. Bal Harbour Shops is two minutes away and Surfside starts just next door. This is the slower Miami.
What you give up at this end is proximity. The famous restaurants, the museums, the Art Deco district and the nightlife are a drive south down Collins Avenue, not a walk. Guests who want to be out among all that every evening are better off down there, and we'll say so. Guests who want the beach at eight in the morning and a quiet street at eleven at night are better off here.
One more thing worth saying plainly, because it decides it for a lot of people: the difference is sharpest at night. Both ends share the same ocean and the same sunrise. They part company after dinner.

