ok, i will be harsh because you told me to be :P

firstly text is pathetic, really doesn't work too small and boring, it stands out too much and just doesn't go with the rest of the sig.

the Bg is a bit boring and plane/ flat, and a bit monotone, you need to add some colour and variation in it, use curves and level as well as different brushes, filters etc.

i like what you did with the render, but the render is low quality, too small for the sig and the right side isn't blended well.

hopefully this will help.