Having a portable database is a really important part of my workflow as a writer. My research hat is always on, but it used to be hard for me to keep my research notes, bookmarks, text and PDF files well-managed and synced over several Macs in the office fleet. I used Evernote for a while but switched to Yojimbo.
Here’s why. Evernote is great until you decide you want to export your data to another database. That’s when problems arise. Even though Evernote talks a good game about being export-friendly, you’re faced with having all of your rich-text file notes being converted to html.
[Update] Apparently there is some kind of workaround to this, but it’s curious that this issue has yet to be addressed fully by the app’s developers.
Bottom line: it’s your data. It is a mistake to take all your hard work that’s gone into filling your knowledge bucket and compromising with it a proprietary system tries hard to lock you in.