FWIW I'm all about Metadata, myself. I rarely use hierarchy of folders to find a file. I use Soundminer 99 percent of the time. That means that my metadata is key when I search, so I make sure that my metadata is impeccable and I am constantly adding to it with other possible uses of sounds.
I do use proper folder hierarchy and keep the filenames descriptive, etc., but I pay extra special attention to my metadata and ensure every possible reference word is in there that it could be used for, because that is how Soundminer works.
It's extremely important to keep up because I have libraries in which the files are named "WR4719400929288457383" and a word search will never pull it up, however because I use Soundminer, it searches the metadata so the Wrench Drop file named "WRDR485737854" will come up in a search.