I read a lot of reviews of Yep. I just purchased a ScanSnap, so I had to try Yep. It seems that the main thing it offers over Finder is the tagging feature. Both Finder and Yep can search folders for keywords and searchable PDF files.

The tagging feature of Yep is pretty good. However, USE CAUTION switching to a tool like this. The main problem is that Yep uses OpenMetadata rather than the document properties. This means the data is NOT PORTABLE. It will not follow to another computer (easily), nor to a file server, or different Operating System (Windows/Linux). The product seams very useful and cool at first, but when version 4 comes out and they change how they store the metadata, you will be very sorry you invested all the time tagging your files.

I've used other products that use proprietary methods to tag information and learned the hard way to not support products like this. I want any tagging or metadata stored only in the file properties. It will have much longer longevity, be platform independent, and software independent. What if you find a new product you like better in 1 year...

My trials with Yep are generally good. However, I cannot support the product because of the "vendor lock in" approach for metadata.