Here's an update from the trip...
The trip was last two weeks of October, and we were told we arrived after 4 months of no rain. It briefly poured rained for the first time on about our 4th day there and everyday for a couple after that. It was dry as a popcorn fart there. We spent a week at Murex Manado and 10 days at Murex Bangka. Both resorts had mosquito nets, but they were draped over the beds formed in 4 panels, so mosquitoes could easily fit through them. However, the only time I noticed any biting insects was on Bangka in the evenings around my ankles on a couple nights only. I'm not sure if they were mosquitoes or sand flies as I didn't see them.
After asking several locals they all said the same thing: Never heard of anyone getting malaria in that area, but occasional infections of Dengue. Basically, they all knew someone who had Dengue at some point, but it really didn't sound like it was high risk.
After reading this thread and talking to more locals and friends in the area before the trip I decided not to take the Malarone, and I don't think that opened up any risk for me. Unless something changed, I would not plan to take Malarone in the future either.
On the other hand, the diving was phenomenal! Also, Murex Manado and Bangka are both excellent, professional, but also laid back dive resorts. We visited the Lembeh resort as well and were glad that we didn't pay the higher price to stay there for any of our nights in N. Sulawesi - not our cup of tea. There are plans to upgrade the Bankga location to a 4-star level like Lembeh over the next couple years which is a disappointment for me, and I will not go back if they follow through with that.