I was reading up on different boxes and hive styles and came across this article.
Basically, the idea is that it doesn't really matter what you use for your bodies/supers as long as the bees have enough space. I don't actually own any bees, I will be waiting for next season, but my friend recently got into it and so I've been looking into getting hives of my own.
It seems that the mediums are favored simply because they're lighter, but it would seem more cost effective to use deeps for supers instead of more medium boxes. I'm just 16, so the weight isn't particularly a problem for me