We stayed for four nights at the beginning of a 10-day visit to Costa Rica. We were looking for somewhere walkable to town and the beach, but with a pool where we could relax in the shade reading in the hot afternoons. Arco Iris was perfect! We stayed in room #2 - one of the individual cabinas with a covered porch and hammock. Comfy bed, spacious bathroom and dressing area, excellent AC, and perfect porch for watching birds and monkeys.
Daily breakfast was excellent and plentiful. Lots of options (I think we tried them all!), coffee available all day, a cold water dispenser, and so much space to sit and chill - shade or sun. The pool was refreshing and always clean, and the vibe was super chill.
Highly recommend and would be at the top of our list if we return to Tamarindo.