While i agree with you in consistency, I do not agree with your last statement. Since I am more used to using relative paths I have always used relative paths when linking my inculdes and have never had a problem with any of my pages loading the includes.
In so far as mentally traversing the directory tree, again it is what you are used to. By just looking at this:
I know that the page that is calling the image file is 3 directories deep from the root without causing myself any mental angst. In any case I can liken this discussion to that of the Mac vs Windows vs Linux debate. Which camp is right in that arguement?
The answer is: They all are. The reason is because its a subjective debate, much like this one, because the ppl that use those platforms and, are subsequentially proponents of that platform, since the platform does what they need it to do it is the "best".
In our case here, there is no silver bullet into which way is the best. As a programmer it is up to you to decide which type of path to use, which one you are comfortable, etc.
I will only tell you how to do it, not do it for you.
Unless, of course, you want to hire me to do work for you.
Read this if you want to know how to get a correct reply for your question:
^^Took that from planoie's profile^^
^^Modified text taken from gbianchi profile^^