I've been to Ohana twice:August 2010 and August 2011. This meal is always the first meal of our trip

We come in time to watch Wishes while we eat and it is very relaxing and romantic and a great way to start the trip.
Both times we went, reservations were around 9:00 p.m.; right in time for Wishes. Both times we were seated quickly (within 10 minutes of our arrival) despite our fear that others would be squatting for a long time to see Wishes. When Wishes is not happening, the restaurant is pretty loud, which has never bothered me. Some people who may be looking for an intimate, quiet dinner may not like this. However, others who want something more family-friendly will appreciate it.
Our servers were of the same quality both times and I feel as though it must be hard for them to not deliver good service since they are so scripted. I always am disappointed to read reviews where customers feel ignored, but it has not happened to me. I felt that the service was quick, all the different plates were brought to our table promptly. On this note, I can see why some people would be offended about not having enough space between courses, but I feel that this is done in most family style restaurants, including higher end ones. Also, many folks probably come in with the intention to eat quickly and go on to a park as soon as they're fed. Regardless, our service has been flawless each time.
FOOD
The food here is great! It's not signature quality, of course, but it's really tasty. I'm not big on meat so I don't care too much for the skewers, but every year I dream of the trifecta: pork fried dumplings, coriander winders, and the noodles. This part of the meal to me is second only to the dessert. Also, the bread and salad always taste very fresh. Sometimes the meat is a bit dry but this has never bothered me since I don't go there for the meat anyway. I go more for the atmosphere.
I think it's worth it to do Ohana once. If you are on the dining plan, just give it a try. If not, it's not terribly expensive for Disney and well worth it IMO. People will always complain about something. I've always chosen to ignore the negative reviews and have not been disappointed. Go into it with no expectations and see what you think! Good luck!