I have the Navfree Australia map on my iPad and it does seem to work fairly well. I had it going in the car the other day while I was a passenger and I made sure that both the wifi and 3G were turned off. It told me the correct position and speed on the road.
I haven't tried setting a route with it.
One of the reasons I got the iPad was to see if I could use it as an on motorcycle GPS by putting it in the map pocket of my tank bag. I think the Navfree may well do that function.