well its kind of a simple background, not much depth, but the colors look nice and the render looks cool ^^
If it looks a little too sharp, you can go to Edit > Fade Sharpen and lower the opacity of it a little.
The glowish effect doesn't seem that great on this sig, it kind of pixellates the render a bit. Also, agreed from above, the render doesn't fit into the background at all. I think maybe some clipping masks and splatter would help with the overall composition, if you know how to do those. All in all, the sig is not half bad, but you could probably advance it still.