The first time I visited Diamond was thirty years ago. I been eating here from time to time for past thirty years.
They have two menu; one is Americanized version of Chinese food. IE. Sweet and sour pork, ...orange beef.... Mongolian beef...etc
The other menu; ( a sheet of pink paper with Chinese writing). Food in this menu is intended for Ethnic Chinese or Ethnic Asian. They offer the most authentic Southern Chinese food in town. Hefty portion very Delicious and super low price. Food on this menu ... absolutely 5 star.
Decor is mediocre at best. but acceptable.
Cleanliness . Among the worst. However, If Diamond was to compare only with other Chinese restaurants. Then its not so bad.
This place have potential to be TOP authentic Chinese restaurant if they are willing to spend more that a nickle for decors and do some clean up.