Lil' wayne is way too stretched. Attempt to keep proportions equal when resizing to prevent any distortion from occuring next time. The C4Ds used should not only be the main effect medium; Rather it should be a small detailing effect used in conjunction with some brushes, and clone stamping, if you enjoy that effect. The render also seems a bit too distant from the background. This appears to be caused by the direct contrast in background color compared to the colors present in the focal point. The lighting is good. The corners may also need a bit more effects on them, to prevent giving the signature that constrained feel. The text is blending into the background. Attempt to lower the gradient saturation on it, to let some of the solid white show.
Overall, it's mediocre. With a few tweaks, it can be a good signature. Good job.