One thing to note and get over with: the service sucks.
Don't expect too much. In fact, I strongly suggest you tip them badly (if at all) and tell them so that they would change.
Now that we got over that, let's get to the meat of it: the food. This is an above average Chinese restaurant that actually serves authentic Chinese food. None of that chicken ball and other Chinese-American monstrosities that select places offer.
The kicker for Happy Jade are their daily specials. My favourite in particular is Tuesday's Steamed Tilapia for $7.99 I believe. That is a steal when other restaurants offer them for twice or more of that price. It is done well with a delicious sauce and cooked just right.