-Definitely go with a full-width image. Maybe it's just because of my screen res (1600*900), but it looks so much better when it is taking up the full width (in my case I have to zoom in 10% to see it this way).
-It's all grey and sad
I'd throw in some more color. For example, top menu bar and 'Build your own website', 'install your favorite script' .. buttons can be red.
-The footer menu is kind of blurry or jagged.
-The logo doesn't stand out at all. Don't use that other grey copy of the dots. Try thinking about different placement/position (top left maybe). When I switch to smaller media query, the logo isn't even visible on the site - that's your brand. It should be visible all the time! 