We did not stay at the Seaview Bungalows overnight, but rather stumbled upon their facilities during a hike towards Than Sadet Beach. The kindness of the owners enticed us to stay for lunch and a beer. The food was good and the view from the "restaurant" very nice! The owners also offered us a drive back to town which was greatly appreciated! You can trust these people!
If you are looking for an off the path place to stay for a couple of nights in Koh Phangan, I would not hesitate!