We spend 4 days in this place and we would had liked to stayed more days.
The owner is very friendly and share the lunch and dinner with the guest. We eat our best meals during our trip in sulawasi.
I don't think that you can find an best guesthouse on Bunaken.
Concerning the diver center, all the guide are very professionnal and you are directly in front of the best dive sport. It's a good value for money.
Unfortunatelly some wastes comes from Manado. However, peoples clean the beach every day.