Any documents that come in are filed in 4-5 trays depending on whether its personal or professional mail. After a while the trays get filed into maps.
Important documents are scanned.
The scansnap i use is a breeze: very quick, doublesided, feeder scans. The pdfs end up in an action folder which triggers an OCR conversion on the pdf, and that is then automatically indexed by Mac OS X.
If it's a really important doc, i will go through the trouble of moving the doc from the scan folder to a hierarchical folder structure, but due to spotlight I tend to do this less and less. So basically the scanning process is a one button effort.
This setup works perfectly for me since years (and i have a *lot* of documents to manage).