Just back from a week and was not at all impressed with the food there.
Breakfast Buffet at the Marriott included with the room was o.k. We stuck to fruit (could have been riper) yogurt, cereal and miso soup. Omelet station was good, but pancakes, waffles were kept warm under a heat lamp, YUCK!
2 buffet dinners at various Hilton restaurants. Edible, but barely. Dinner at Roy's inebible...had to send ribeye/rice dish back as it was so salty. They then bring out a filet (more expensive I believe) as a replacment that was flavorless. The restaurant also has bad acoustics...serious LOUDNESS. Merriman's cafe was decent, though not extraordinary. Saturday night "Clambake", all you can eat Lobster, crab, clams, mussels, etc. at the Mauna Kea was good, but for $80/pp it did not have the selection that you'd find at a Four Seasons Buffet for the same price.
Pupus/Cocktails at the Four Seasons Beach Bar were outstanding as was the service from Barman Tom. Lunch at Don The Beachcomber in Kona was a somewhat greasy burger & fries and a quesadilla. Nothing great there.
We stopped not far from AKAKA Falls at the "lunch stop" at the restaurant in the Blue Lotus Gallery in Honokaa. We had the daily special..a fish curry and a chicken curry served with rice & salad. My husband had a tropical smoothie. Everything was delicious. By far the best meal of the trip and cheap too, under $10 bucks.
If it had been up to me, I would have avoided the hotels (except 4Seasons)like the plague. Seek out the hole in the walls where the locals eat.