Little point in holding onto revs above 5000rpm anyway. Just viewing power/torque curves will confirm that both are tailing off then.
Although I agree the last RPM aren't going to gain you much, the torque/power curves on their own don't tell the full story - it's a combination of gear ratio and torque at the relevant rpm. i.e. if you're really going for it (e.g. circuit racing) you are usually better off holding on to the current gear even if power is dropping off.
