I'm curious which vid and sub file you are using. So far I haven't come across a truly bad Chinese sub file yet, but of course I've sampled only small fraction of all Chinese subs.
I underatand Google or most machine translation could epic fail for Chinese jav subs. There are slants in those subs, and both Japanese and Chinese have similar but different tendency to euphemize/sanitize dirty words. Plus there are often minor typos thats easy for human to detect but fucks up autotranslator. And the missing confusing puncuations and line-breaks thats unique to subs but uncommon in normal text. Unless Google or some engine has been tuned for these quirks I think you will find human translator still has a big advantage.
Perhaps i am just being too critical of the chinese subber's work. Anyway - i have decided against using other peoples work and will instead do native translations myself. Will post one in a couple days!