For weekend trips we do stay at a AI in Punta Cana. Most stay at the AI's because for them it is a "no brainer". All the food, drinks, etc..for one set price. I can see why some go 1-2x a year. Is it cheaper, depends. I have been to AI's here that I have seen people killing themselves to get their monies worth of booze and food. In Punta Cana most go for the beach and of course there is a wide variety of AI's to choose from. They rarely leave the resort since there is not much going on. There a few places to see and hang-out but you will not get a good glimpse into the local culture in Punta Cana. There are also lots of package deals at decent prices. The North Coast use to be the place for AI's back in the day but not so much now. But on the North Coast they have much more to offer outside the gates of the AI in terms of experiencing the local culture. I would say for first timers a AI may be the way to go if your budget permits. I just like the OP also prefer to travel in low season, much less hetic and stressful.