Sometimes, it’s the little things that make all the difference. One of the best features of the R2005 Mtext editor is the ability to quickly exit (while saving changes) by clicking anywhere in the drawing editor. This beats trying to pick the tiny OK button every time.
To quickly hide all toolbars, and windows in the AutoCAD screen (such as tool palettes), use the shortcut Ctrl+0. This devotes all your screen real estate to the drawing editor, with the exception of the pull-down menu and the command line. Use the same shortcut to toggle your screen back to normal.