Definately not an event for those that don't like crowds. This is as close as you can get to feeling like you are in a busy urban Asian city like Hong Kong. Hundreds and hundreds of people swarming around you, all with the same purpose in mind: FOOD.
The ambiance: it's either you love it or hate it. I know some people who have been here once and swear they will never come back and those who come every year because they love the busy and lively atmosphere.
Prices are Ok. From what I remember, it was $5 for stinky tofu, $8 for an oyster omelette, 3 lamb kebobs for $5.
If you don't want to end up lining up to an hour to get one of the more popular food items, I would suggest going during the day time. It gets so pack at night that it is difficult to move from point A to point B without worrying about someone's lamb kebob stick poking you in the eye.
The most popular choices are the taiwanese syle stinky tofu, oyster omelette.