Have sat down for dinner several times; each with mixed results so far as service is concerned.  The lunch special is a cheapskate's bargain (unless you drive a Saturn with a knitted afghan and a fresh box of Kleenex in the back window, wear those "Terminator" sunglasses, and still mourn the demise of the Thriftymart restaurant and it's blue-plate specials).  If you're in a situation where you'll end up paying for everyone's lunch, insist on Great Wall.  I've even gone there an hour after the lunch special was over (according to the clock) and with the slightest whining we were able to order from the special menu, and at the lunch special prices.

I haven't ever had "really bad service" at the Great Wall but oddly enough the worst service I've had at GW has been at dinner.  I say oddly enough because I think most folks tend to tip better at dinner - it stands to reason the waitstaff would work harder to "tip" the odds in their own favor with regards to percentage.  I rarely tip 15%, normally I'm leaving between 20 and 25%.

Service issues aside, the Mu Shu Pork is really good, even as take-out.  They also make chicken and shrimp Mu Shu but the way that plum sauce hits the pork makes it a must-have.

Orange Chicken: Don't forget to say you'd like it "Old Style"; trust me it's better.

Pan-Fried Noodles is an excellent choice but beware; it's a lot of food.  When you order it out they give you the big hard tangled noodle-cake and the broth with meat and veggies separate.  It's easy to break off part of the noodles and portion off some of the other ingredients for a single serving; that way it tastes restaurant-fresh each time.  Almost anyone can eat twice on one take-out order of PFN and some people could go three times.

Unless you're a white-rice nut or your meal has something that specifically demands white-rice, go for the BBQ'd Pork fried rice.  If you've ordered out be sure and eat it all while it's fresh because it's hit-or-miss quality on a reheat.  A few drops of water and about 20 seconds in the microwave will sometimes (seldom) save it.

Lastly, the poor front desk people; they gotta' deal with customers coming for their the take-out orders, deal with large seatings and handle all the phone traffic be it take-out, reservations or just fool questions about MSG.  Throw 'em a bone once in a while; I try to tip $2.00 for the person who expedites my order (hands it to me).  There's a particularly nice lady at the front who has been there for years; I don't know what kind of Asian she is, but she's definitely not Cauc-Asian!  She looks as though she might hail from the Wu-Tang Dynasty (Die-Nasty) of the Pu-Nanni Province.  You should be paying $2.00 just to look at her... with clothes on!