We were very skeptical to eat at Kouzzina's after reading the reviews here too. But my DS loves Cat Cora and Iron Chef so we decided to try it with low expectations. We were very pleasantly surprised and had a fabulous meal and experience! The service was the best we had of all TS (surprisingly so), our waiter was wonderful! The food was top notch from start to finish. We are really picky about food, too.
We would love to go back for breakfast sometime as we hear that is good.
I know it seems like Kouzzina (and most TS restaurants anymore) can be so hit or miss, but it was great for us.
If you are really concerned about the meal for a wonderful occasion is perfect, I would probably stick with a restaurant that gets CONSISTANT positive reviews, (perhaps a Swan or Dolphin restaurant? They seem to get great reviews) or be willing to give it a try.
Have a wonderful time celebrating!