I would definitely recommend taking advantage of eating at Kona while you are staying at the Poly - it is soooo good, and really convenient since it's in your resort! I ordered the pork chop, and it is maybe the best piece of meat I've ever eaten in my life. I am a total carbs person and usually don't care for meat, but at this meal I actually passed up the delicious mashed potatoes to save room for more of the pork chop. I don't think that's ever happened before in my life!
Ohana was great, too, but we had to wait around 30 minutes to be seated, even though we had a reservation. I know this is common practice at a lot of restaurants, even during low season, and not worth complaining about. And if I wasn't trying to entertain a 1-year-old in a super crowded lobby, it may not have mattered that much. But it was pretty stressful trying to keep him happy and by the time we were seated, we were pretty worn out. The food and service were great, so it might be worth it, but I don't plan on going back until DS is a few years older