I love the screenshot and what you did with it, and the background looks alright, but it lacks in blending and flow and a more complex bg.
"Leenum"!? Rofl. That's new. Anyways, I like what you did with it. I wish the shot itself could look like that. Lol.
oh snap.. i been calling you rname leenum this whole time.. just noticed its leeumm as in Liam.. lolz
Well, the spartan isn't blended well and the bg is very bland, but the smudging is ok, just take the edges of the spartan and smudge them a little. Oh, and the c4d on the right goes against the flow
personally i like it, but yes, the line on the right isnt looking exactly right, but it does put a little bit if a asymmetric look
The blue visor is sick and the shade of black and white you chose makes the guy look badass. The background is boring, no offense. Put some excitement to it. But if you ask me, adding C4D's for this sig will ruin it. This is just the type where you don't need them.
Some parts of the c4d aren't really consistent with the flow. The right side is a little off. I like how you kept this sig a bit simple, however I would like to see more blending in this sig to give it more depth. Also I think that the render was oversharpened, but not by much. Typically you can oversharpen armor off halo 3 in sigs, just because it tends to look pretty good, but I still think you over sharpened a litte. Other than that I think it looks pretty good, I understand that it was a pretty quick sig. Try slappin on some white text and see how it turns out.