It would suit my way of working (like in CDA4A) to be able to add media to the pool *without* it going straight to the tracklist.
Without this, I can't see the point of having a Media Pool at all, except for convenient removal of stuff (although it still doesn't remove the track markers when you remove the media, which I guess is another thing...).
I guess what I mean is that there should be a right-click option to "Add Media To Pool', or at least an right-click option to 'Open Media'as on toolbar, and operate on the tick-boxes to 'Add To Timeline' / 'Create Tracks'.
Uh, it has that. Right click on a file in the Explorer, and there's an "Add to Media Pool" command. Use "File > Open Media" and uncheck the "Add to timeline" and you'll be adding just to the Media Pool.
The right-click "Add..." in CDA4 brings up the Add to Audio Pool dialog, which is exactly replaced by the "Open Media" dialog in CDA5 (accessed from the main or Media Pool toolbar or Ctrl+Shift+O). They do the same thing.