I spent one night at the Riverside in January after a dive trip, and had a great stay. The service was informal yet impeccable - I felt like I was staying at a good friend's beach-side mansion. My room was spacious, good-as-new clean, bright and cheery. The hotel itself is situated beside an estuarine (not brackish or smelly though) stream with the beach in view. It has a very tranquil vibe; it feels slightly remote from the rest of Khao Lak, which is actually only a short walk away. The manager, Peter, is earnest, friendly, and sincere - he gave one of the most detailed and professional briefings about the room and amenities I've ever heard. He and the owner Ja were such warm and charming folks, they even arranged for me to have a massage and meal at her nearby restaurant (and she personally fetched me to and fro!), and an extra-early breakfast the next day as I had to leave for the airport early. It was just a one-night stay, but I had a wonderful time.