No, mine is inverted twice - once digitally (by reversing the polarity of the screen with an additional chip), and then again with the polarisation film.
If you put an inverted screen straight in, you'll get image quality as good as mine, but reversed polarity (black=white, white=black). A non-inverted screen will have the correct image, but doesn't come out as sharp as double inverted.
So it depends on your skill level etc. The screen installation is fairly easy apart from removing the reflective film, which was a pain. But the biversion chip is tricky - about as tricky as mod-chipping or RGB modding a console.