shift points

Where do you guys normally shift your cars? Seems if I let the tranny shift itself, it shifts at only 4000 to 4500 (MAX) rpm. Is this a little too low? I have rarely seen the red LEDs on my factory tach (which begins at just over 5000, right?), and I have NEVER hit the rev-limiter. Do you think I would have much to gain by holding the car in gear until I see a red LED?
Do you have a aftermarket tach you can use to accurately check those shift points with? The factory LED arrangement is pretty unreliable. As nasty of a job as this is, you may need to drop the pan and see if you have the right governor in there. If so, it can be modified to raise the shift points.