Here is mine under construction. The gray shows dirt and leaks, probably harder to keep looking clean. I know I'm not supposed to have leaks. I clear coated the intake manifold to try and keep the blasted aluminum look, It still looks good but not much contrast with the gray. I painted my exhaust manifolds with some POR-15 high heat product after sand blasting, that turned out to be a waste of time. One thing I would do differently would be to paint the valley pan. I left it raw and it doesn't look so good now.
Edit: sorry about the pic size. Right click on pic and select "view image".