I went to Wai Wai with my boss yesterday. The service from our waitress was so-so, and it wasn't too terribly busy for lunch hour (we walked in at 12:15 p.m).
The food was decent; I liked the steak and onions and I liked the fried rice, but nothing stuck out as particularly bad or good. I think the lunch price was around $7, which isn't bad at all.
For this price point, I wasn't thrilled, but I wasn't appalled. There was a pretty good selection of your Chinese-American staples, and, for a buffet, the food was warm.
Like I said, nothing really stuck out as being good or bad. I'd give Wai Wai another shot because of the price point and variety. Just don't expect gourmet five-star dining.