The color, IMO, is terrible, and it seems that there is barely any smuding. It looks like the sig took you 3.4 seconds. There is absolutely no flow or lighting. Also, the render is pretty blurry.
Well,I took about 10 min and,color is not my best.But i made it form the render and a white back ground.Some signature don't need flow (Most do).And the lighting by his side,not may best.But all of its smudge.