Just lived there: Las Terrenas, with Punta Cana and Santo Domingo on the list. Writing up the notes from the road.
I recently lived in Las Terrenas, testing the Dominican Republic for nomad coding first-hand: internet, cost of living, long-stay housing, power reliability, walkability and work spaces. Punta Cana and Santo Domingo were also on the route.
Notes and the full guide are being written up from what I lived there: no secondhand data, only what I actually experienced and measured.