Good tool (preferably as Firefox Addon) to check layout and formatting of Website?

I am looking for a tool (preferably a Firefox addon) with which I can see at first glance what the pixel distance of objects to each others are, what colors are being used and which font + size is being applied on a given website. Currently, I am using the Firefox Webdeveloper Tool going through each section one by one but this is rather tedious work. Should it help paint the picture, imagine me in all black and white, loudly yelling "there's got to be a better way!"

So, does anyone know of such a tool that can accomplish this? Or do you maybe happen to have another tip how to streamlin my QA-process?