one slight issue, if you try to open image/link/flash sidebars in fullscreen, firstly it doesn't work (obviously) and when you leave full screen the CMS window is broken and needs to be refreshed.....
It seems that having those custom buttons as sidebars is great when your in the CMS but as soon as you try to do anything with the HTML editor outside the norm they become a real pain (not to mention the fact that the image upload button doesn't work with flash 10 making the whole tool pretty pointless).
I'm actually going to try and add tiny MCE's official image manager in the project I'm currently working on, it's 30EUR but looks pretty darn good and should work in any context. The only after that is the link editor as sslink is way better than the tiny MCE link primarily because you have a TreeDropdown to select internal links rather than typing out the URL (yuk!). I wonder how easy it would be to make it a popup window rather than a sidebar......