Pretty cool background, it fits the render pretty well. You didn't really get the render to blend much with it though. You did do pretty well with depth, but still not the best, because it looks like the render was just placed. I see a little blending on his left shoulder, I guess thats where the depth is coming from. The text is not the best, I don't think it should be where it is now. Perhaps bringing it closer to the focal. I don't really remember what your previous work looks like, but I think this sig is decent, there is room for improvement.
Thanks for the critique. I am at my grandparents for 2 weeks without photoshop so no fixes will be made until then.