I am in the hit or miss category, though based on that I would say overrated, because if it was worth every penny I personally feel it should be more consistent. I know that anyone from the chef to the bartender to the wait staff can have a bad day, but there are just too many back and forth reviews.
The first time we went was on an extended family trip and we chose that restaurant to celebrate my grandparents 75th and 80th birthdays. I was the one that suggested Ohana based on good reviews from this board, but I will admit that I was very nervous about the suggestion because of the mixed reviews. But we wanted something where we would be able to see the fireworks and not everyone was open to paying what it would have cost to try California Grill. That time was fantastic. The food was delicious, the service was just right, not too slow or fast, and even though we waited almost 45 minutes after our ADR to be seated, it was worth it because our party of 13 got a table by the window and we were able to see the fireworks at MK.
DW and I liked it enough that time that we went back just the two of us on a later trip and our experience was almost the exact opposite. We couldn't get drinks or water refilled, food was slow and came out lukewarm, and while we weren't there to see the fireworks that time we had our backs to the window and were basically just seated looking into the center of the restaurant. We talked and we would not rule out going back at some point, maybe, but it won't be anytime soon if it does happen.