It also kind of depends on what you want to do on your vacation. We love South Walton/30-A and head out there regularly for day trips and occasional weekends (usually without the kids), but there aren't a whole lot of things to do out that way. They do have concerts and events and bike/kayak/paddleboard rentals, etc., but for the most part you don't have a bunch of attractions. The trade-off is getting the quieter, slower-paced, relaxing beach town vibe. A lot of people are looking for exactly this, which is why it's gotten so popular.
But Destin has all the "stuff" to do. The Track go-carts and mini-golf, Fat Daddy's arcade, feeding the alligators at Fudpuckers, Big Kahuna's water park, the movie theater/BassPro/fountains at the Commons, Uncle Buck's bowling alley, all the stuff at the Harbor walk (zipline, hamster balls, outdoor concerts, watching fishing boats come in), and the same types of touristy stuff at Baytowne Wharf, more restaurants, the charter fishing fleet, parasailing, dolphin cruises, jet-ski rental, etc. The trade-off here is the crowds, traffic, hustle and bustle and that almost all of those things cost extra money. Just something else to consider. If it rains, you'll probably be driving to Sandestin/Destin anyway to get to movies or bowling.
Also, it's worth mentioning that outside of Watercolor, there aren't really resorts on 30-A. We enjoy renting beach houses, but some people may prefer on-site dining, swimming pools, maid service, concierge, etc. that you get in a big resort/hotel that you won't have in a beach rental.
And just to throw it out there... it's a little further at 4.5 hrs per Google, but Savannah/Tybee Is. is a really cool area and something totally different from what you get along the Emerald Coast. I only got to spend a day there on an off day on a business trip, but it's on my list to take the family back for a real vacation.
