Here's my question...Don't u wanna shift at the highest rpm possible?

The reason I ask cause I have been pondering my shift points and got to thinking what makes it different? We'll use my gearing and tranny variables for this excercise(Class in session )

Final drive ratio: 4.56:1

Tranny ratio: 1st(3.37) 2nd(1.99) 3rd(1.34) 4th(1.00) 5th(.67)

I know to shift from 1-2 at 7k but alot of the other guys(n/a DOHC) may shift at 6800 on the 2-3 and 6600 on the 3-4. Correct me if I'm wrong but wouldn't a car in either 3rd or 4th gear at lets say 5500rpms would be going slower than a car in 3rd or 4th at 7K rpms? So if you would shift the car at a lower rpm, wouldn't that have a result in a lower mph? I know about the peak power and powerband that u want to be in when your racing. But it seems more ideal to have a car at a higher rpm at the traps for more mph? I'm cornfused. Thanks. -Mark