Two very nice DLLs, I can see myself using DCX when it's finished but I'm not a big fan of cluttering up my screen with toolbars, etc. so I probably wouldn't use Ultradock.
I did try Ultradock, however, and found that when undocking a dialog it completely closed mIRC. I don't know if I was doing something wrong or whether it's the DLL.
To get this problem I would dock the dialog using the init event, then I would undock it via the command line at which point mIRC would close.