I’ve been to the Caribbean side around Puerto Viejo. I’d recommend Hotel Banana Azul in Playa Negra. They have villas as well for a less rustic experience. The whole area from Puerto Viejo to Manzanillo is pretty nice, gets more rustic further south you it seemed. I know there is a tarpon lodge in Manzanillo. A lot of jungle along with the beaches. I’d recommend taking the puddle jumper from San Jose rather than than making the drive.