Holy cow that looks awesome! You can tell you spent a lot of energy making this look great. Excellent job, dude. That's what I'm talking about - clear and crisp images at any resolution/size
Since you asked for comments, this is what I would do:
Think about the whole CP design. Is it going to include the black bar up top and the lines around the edges with the yellow gradients? If it was me, I'd put spidey on some type of dark background, maybe with a subtle black/blue vertical gradient - just so it's not so bright white.
And I'd suggest maybe finishing off his left hand (his right), I know the original doesn't have it finished, but it looks weird unfinished. He just looks a little offset here.
Anyways - now you have a great piece you can use for sideart or marquee or whatever - maybe make a mcfarlane-ish spiderweb theme for the artwork and add him somewhere.
Again, looks great