I recently have purchased a license of FoxTrot Professional and it's really one of the best software investments I've made:
At work, it has signified for me much less stress to find that letter, that PDF, that report, that email where the information I urgently needed was —having very often someone at the other side of the phone waiting for it. I also use it at home to find that citation I needed among my research papers or OCR scanned documents.
I used to have other database applications, more tag orientend, but having to deal with Gigabites of texts, it simply was not the best approach. Now, although I still classify my info in mayor cathegories, I don't spend more time in tagging files, trying to guess when will I need to find them in order to arrange them accordingly. With FoxTrot I can find the context in the document I'm looking for, and not just the file to search in it. And the time scroll also lets me narrow the results, in real time.
I also use Yojimbo very much, and it was a so nice surprise to find out that FoxTrot even searches the Yojimbo database without necessarily having it running.
A computer is as powerful as the programms you run in it, and FoxTrot has really empowered me to instantly find the right information. It's excellent!