I have visited the North Coast several times, lived on the South Coast and visited Las Terrenas once for a few days. Personally I loved Las Terrenas and thought the beaches were better than the North or South Coast, I loved the selection and standard of the bars and restaurants, and the European flavour is obvious in the selection of food in the shops and the bars and restaurants. For example several European products in the supermarkets, great wine selections, lovely French bakeries. The whole vibe of Las Terrenas is like a combination of St. Tropez mixed with the DR which I personally enjoyed. What I didn't like was the lack of electricity as I was there when the change over from the private system was happening and no one seemed to have sorted generators and inverters yet, and the amount of traffic, especially quad bikes in the main street. I think the lack of medical care used to be an issue, but I understand there is now a clinic there. if I was coming to the DR now and looking for somewhere to retire, it would be at the top of my list. Having said that, I am European so it may not be as attractive to North Americans as it is to Europeans.
Matilda