I worked with DevonThink a little and found it feeling too powerful. The problem I have with all these types of apps is that you need to commit to just one and tackle the learning curve. A 30 day demo (though many are longer) is usually not enough and it is intimidating to put ALL your data into something your just trying out. As a scientist I need to connect ideas from many places (seminars, conversations, reading) and find I use different note taking media depending on the context. How do I efficiently connect my paper notes from interesting seminars with the PDF files of papers I read? The only answer I've found to date is "quickly." I need to condense new ideas into notes I can refer to and expand. Paper is good for me right now. A decent full solution for me does not exist as of yet. Though I still hope for one just as I hope for better speech recognition so I can type less!

So, some suggestions for test driving these apps:

1. Lightly use many apps to find the one whose controls and work flow "fit" your own style. There are so many choices, you should not have to adapt your behavior to accommodate an app. It should be the other way around
2. Once you select a style, commit all data possible to using that app for the demo/trial period. Get it all in and work with it. Make it your only choice - dive into using it and see how it feels.
3. At the end of the demo, ask yourself if you made any new connections between ideas that you found interesting of beneficial.

It may be something small, but if it is a consilience of your knowledge and leads to something new and exciting (or useful) to you, then I would say it is a success. The other side of that question is, did it cost me any such desired ideas?

At the end of the day you don't want to attempt tp boil the ocean. Don't be afraid to call something crappy if it doesn't fit you. Just because everyone else uses something doesn't mean it will fit you, or that it even fits them.

Goodluck young grasshopper.