Codegen cases are cheap and also insanely cheap constructionwise. The metal in the cases I've worked with is very thin, they have lots of sharp edges too and very restrictive fangrilles (have become a bit better in the newer models though).
And they have the most underpowered psu's (if you get one with an orignal CG psu) I've ever seen, the cheap ones in ATs recent roundup - which they say is very bad - iis far above the CG psu's when I compared a few cheap ones (had to build some rigs for some friends) a while ago.