This program may be considered the state-of-the-art, but I'm not convinced that is saying all that much. It still has some problems.
for instance:

• A system which is supposed to help you manage data, under OSX, that doesn't offer spotlight support is just a disconnected database.

and worse:

• The program is buggy.

The second one must be qualified I suppose. It is all too easy to get the program into a mode where clicking things in the list on the left, does not display or update the document area, or selecting links only highlights the item in "unselected gray" in the list rather than actually displaying it. From that point, about the only thing you can do is close and relaunch the application. Additionally, from a usability standpoint it suffers serious flaws. As an example – the various modes of the program are nice, but it has a tendency to "hide" things which you think should be displayed in the lists, and reveal others which you wouldn't think would be there depending on what mode you are viewing in. I think it needs some list handling conventions which it sticks to no matter what display mode the program is in. In general, it the program acts as if it takes one mess of data, and makes a different mess out of it with its own set of rules. On the plus side – it has powerful and fast search. That's about it though.