Load time versus bytes in

How is the size of the site factored in? Would it be a good comparison to take a site and then divide fully loaded time / bytes in or would this be too inaccurate in comparing several sites and their hosting speed?

It COULD be since theoretically the bytes in is the useful content you are trying to deliver to the user. The problem with it though is that you can’t be sure that the site is delivering the least bytes possible for the given content (gzip and image compression are perfect examples).