Hi,
Right now, you can set a hotkey to open Take Note in the sorter, but there isn’t any key that can close it.
Escape, eject, some combination of those with option or cmd don’t seem to do anything.
Pressing the same hotkey to open it would intuitively seem that it would close it but it doesn’t do that either.
I think that either escape, or preferably, the hotkey itself, should close the sorter Take Note if I decide I don’t want to use it anymore.
How about Command-m?
It’s good to know that cmd-m works, though it only works when the sorter itself has focus (not global).
Although that is the case when you just open the sorter some of the time, it isn’t all of the time (say, you open the sorter twice, the second time it will no longer have the blinking cursor can’t be minimized).
It’s not the worst thing in the world, but I’m just making a suggestion.
I’d personally prefer, and would suggest, just having the global hotkey toggle opening and closing.
A bit off the original topic, but I’d also love a global “Show Groups” as well. 
Again, neither are essential, though I’ve basically been hacking it through creating macros and scripts to make them “global.” It would be a much faster process with less windows flashing in and out of focus if these were both global functions.
Giving the context I’m speaking from, basically, I love all of the functionality in DEVONThink but want data entry and capture to be as easy as say, Yojimbo, makes it.
The sorter is an interesting concept, though it doesn’t autopopulate and you can’t just put all the groups into it (without it taking up an ungodly amount of screen real estate). Show groups seems like a good intermediary to me.
With show groups and take notes easily accessible, Yojimbo really has nothing on DEVONThink.
Just uncheck the General preference labeled “Hide Groups panel when inactive” and it will stay visible all the time…
I noticed that you could have it stay around and on top of other applications. Mainly, I meant toggling.