If you have a fast bike and are studly, then ride with the cars.

Otherwise, if the sidewalk doesn't have alot of driveways and such crossing it, then ride there. Make sure you slow way down and look for trouble at driveways and parking lots. Walk your bike through any crosswalks. Take your time.

If neither of these are true, I don't have a good answer. If it were me, it would probably depend on which bike I rode and how much traffic there is. If there isn't much traffic or if it is bumper to bumper, you can probably ride in the road. Sounds like it is usually that awkward in between level of traffic. Constant stream of cars that want to go faster than you. I guess I'm leaning towards the sidewalk like you currently do.