We have been to Chung Moi a few times and I have to agree, the food is pretty good and the portions are really big. But the restaurant is in a sketchy area and the interiors are beyond deplorable, dark and dingy. The lady (owner methinks) is always in a bad mood and have heard her scream expletives at people on the phone - bad enough that we had to walk out with the kids.
What pushed us over the edge was last time we took some friends over for dinner and before we could pay our bill the wait staff started emptying our leftovers and trash onto the table (the table is covered in plastic). That was uber revolting and we had to run out of the restaurant.