Texturing Basics - Adding detail to materials while condensing your UV map

Allow me to paint a picture to help better clarify my confusion.

You have a box, and it's unwrapped - all sides of the UV are stacked on top of one another so that you are able to use a single repeating pattern, say something like shingles.

Now, would it be better practice to leave it that way and add decals in order to make each wall unique or separate each side of the box in the UV map and just individually texture each side?

I hope this is clear enough - Thank you all in advanced!