Hi domo - like Michael said, those are just folders in the screenshot, not libraries. Honestly, from what I researched in the forums on people’s thoughts, and my own conclusions in my own thread with Michael’s help - there’s really no strong reason to even use more than one library unless you need to be able to store them completely separately on different media, or want encryption on only some things. (or I suppose, to keep tags/labels and such segregated for different libraries if they’re different projects - at least I think the tags are per library)
I just wanted to point that out since I can see how the screenshot LOOKS like multiple libraries… Since it’s all a folder structure anyway, for me, I figured just one library is fine, which makes the multiple libraries in the left pane not even an issue.
I would also say, I trialed using DevonThink, and while at first, that amount of customization seemed powerful - it got very overwhelming, very fast, to have so many different containers at a high level! I realize that software probably allows for more customization of what shows, but be sure you need that level of power/tweaking - it takes time to set up and maintain such things, also.