Well, I finally got around to putting these caliper covers on yesterday. I've seen guys paint their calipers but the color still tends to flake off and fades after awhile. These are T6 aerospace aluminum and powdercoated so they improve the looks but don't give any performance gains. As for weight, they really only weigh but a few ounces and are supposed to reduce brake dust getting on the rims.
Here's a couple of pics.
MGP Caliper Covers