This place automatically gets a decent review for doing North-West Chinese food. It's a part of Chinese cuisine that gets very little love in the West.
The liang pi I had was a bit bland. I thought it needed more vinegar and salt. The scallion pancake was great (though I didn't expect it to be deep fried). And although fu qi fie pian isn't strictly North Western Chinese food, they pulled it off really well. Would get it again.
Overall, if you are not familiar with this part of Chinese cuisine, Homemade Ramen is a good place to start.