DjDiverDan is correct that the southern AI resorts are isolated, but I disagree that the isolation is a negative. As others have noted, it really depends on what you're expecting from your vacation.
San Miguel is a small city with a population approaching 80,000. You will definitely not feel isolated there as it as all the trappings of a city. Yes, restaurants abound as do shops. But people abound as well, lots of them. In honking cars, on scooters, on foot. If your idea of a idyllic Caribbean vacation does not include noise and congestion, you may appreciate the isolation of the southern resorts. If your idea of an idyllic Caribbean vacation includes visions of beaches and local flora, you may appreciate the beauty of the southern resorts. On the other hand, if you are a foodie who wants diversity in meals and do not mind congestion and noise, then the "city" may be better for you.
The other "plus" of staying to the south is that the majority of dive sites are located that way, thus it can be a much shorter boat ride to the dive sites. If you tend towards seasickness or are just impatient to get into the water instead of sitting on a boat for a half-hour ride to the sites, the location of the southern resorts may be better for you.
The thing about Cozumel is that it's very diverse for a dive locale. If you go to Cayman Brac, you have a couple options. On the other hand, Cozumel offers many permutations of how you can plan your vacation. There's a lot of experience on this board. I've been to the island nine times and have dove with seven different dive ops, but my experience pales in comparison to some of the people here who have been going there for many years, sometimes multiple trips a year. And there are others here who own vacation homes on the island as well as ex-pats who call it their permanent home. Browse a bit, get an idea of your options, decide what exactly you're looking for, then as robint suggests, let the forum know what you want and you will receive all the tailored advice you could need.
San Miguel is a small city with a population approaching 80,000. You will definitely not feel isolated there as it as all the trappings of a city. Yes, restaurants abound as do shops. But people abound as well, lots of them. In honking cars, on scooters, on foot. If your idea of a idyllic Caribbean vacation does not include noise and congestion, you may appreciate the isolation of the southern resorts. If your idea of an idyllic Caribbean vacation includes visions of beaches and local flora, you may appreciate the beauty of the southern resorts. On the other hand, if you are a foodie who wants diversity in meals and do not mind congestion and noise, then the "city" may be better for you.
The other "plus" of staying to the south is that the majority of dive sites are located that way, thus it can be a much shorter boat ride to the dive sites. If you tend towards seasickness or are just impatient to get into the water instead of sitting on a boat for a half-hour ride to the sites, the location of the southern resorts may be better for you.
The thing about Cozumel is that it's very diverse for a dive locale. If you go to Cayman Brac, you have a couple options. On the other hand, Cozumel offers many permutations of how you can plan your vacation. There's a lot of experience on this board. I've been to the island nine times and have dove with seven different dive ops, but my experience pales in comparison to some of the people here who have been going there for many years, sometimes multiple trips a year. And there are others here who own vacation homes on the island as well as ex-pats who call it their permanent home. Browse a bit, get an idea of your options, decide what exactly you're looking for, then as robint suggests, let the forum know what you want and you will receive all the tailored advice you could need.