If you inspect the calipers and find that everything is moving freely and nothing is stuck and still have uneven wear I would have the rotors turned.
If the wear is not drastically uneven and your rotors have smooth surfaces then you don't necessarily need to have them turned. However if your rotors are smooth but the brakes pulse that means your rotors have become warped and do need to be turned. I haven't had mine turned yet on my 91Si because everything is wearing evenly, the rotors are smooth and there is no pulsing. :driving: