[mikejt]

Actually, I've been using OG for just this sort of application (lots of figures for technical papers, presentations, etc.) and, although the interface and style took quite a while to absorb, it has been quite a success. I also own Intaglio and EasyDraw for special purposes (they *are* more MacDraw-like, and Intaglio will import ClarisDraw docs, and EasyDraw has dimensioning features, and both will import PDFs much better). Intaglio is very promising, and its UI is pleasant, while EasyDraw has a rather amazing feature set but garish and cluttered UI.

Still, OG has the best/simplest UI (fewest windows/toolboxes open), and is by far the best when it comes to doing block diagrams (connections work, magnets work, orthogonal lines with adjustable radii, shadowing, line labeling that is easy to adjust, linkback to Keynote, good typography control) ... works really well.

If you want OG to act like Canvas or MacDraw, try disabling all the automatic connection features (inspector->properties->connections) for both lines and shapes and things will work like you may expect (or better, since the various smart guides are so useful).