I live in a city just north of New Smyrna and it is definitely a good choice if you want something less expensive but still close to nearly everything. There are 2 colleges in the immediate area both of which attract a diverse group of people, but we still skew to an older demo, like much of Florida. However, our average age is more middle age, and not senior like NSB tends to be.

It isn't a major city as you are probably aware, so if you are looking for that I'd pick Miami, Jacksonville or Austin. Jacksonville has a pretty well established startup ecosystem, and until recently it was better then Miami IMO. Although now I'd choose Miami of Jax.

I like where I am, it is a great community, low cost of living and we have all the key things needed to run a business. Plus I am within an hour drive to Orlando, ~2 hrs to Tampa, just over an hour to Jacksonville and just under 4 hours to Miami. So I can get anywhere I need easily but I don't have to pay crazy living expenses and I can live in a smaller community that has great beaches etc. There is even a number of investors with property here (and live here) and whom you can network with as well. In this area there is a pretty large group of people from outside the US which is great, but is not common IME for smaller communities.

FWIW: I have lived in Austin, Melbourne (FL), New Smyrna (and surrounding area) and Denver. Hands down for life style I love where I am. Austin is also really hard to beat, I just happen to love being near the ocean. I haven't lived in Miami (just visit often), but I'd also have no problem living there. I wouldn't choose Jacksonville, but I have worked in Jax off and on. You mention Bahama's too, we have a couple of companies that fly to the Bahamas direct out of either Daytona or NSB airports which is pretty nice.

If you have questions you can find my email in my profile, happy to tell you anything I can.