The curve tool in OpenOffice is definitely difficult to use. For the most part I don't use it in my maps.
The other disadvantage that I've found is that there is no list of layers that shows their status (locked/unlocked, hidden/visible, printable). Changing these toggles in OpenOffice is cumbersome. I used to use EZdraw and that had a layers table that you could select and unselect checkboxes to change layer statuses. Much nicer.
The major advantages of OpenOffice are that it is free, and it has a very shallow learning curve.
I noticed a couple things said earlier in this thread two years ago that need corrected/clarified.
OpenOffice Draw DOES have a multi-point line tool. The icon for it looks like a arbitrary-shape polygon tool, but it works just like a multi-point line tool.
Lyman stated that you can learn OpenOffice by spending a couple hours going through my manual/help file. That manual is mostly about drawing maps with OpenOffice. If you already know how to draw maps, and have some previous experience with a drawing tool such as Illustrator, Corel, or even Powerpoint, the learning curve for OpenOffice Draw will be a few minutes.