I was talking to the PLT desk the other day while trying to upgrade some tickets using miles. She had put in 3E. I didn't know whether it was an M80 or 757, so I asked if that was the bulkhead. She quickly said no that it was a 757. She then proceeded to say that "they" know that the bulkheads are the least preferred FC seats and that unless they are requested, the res. agents will fill up all other FC seats before assigning bulkheads. This may not relate to the sticker upgrades but at least they know that bulkheads suck and instruct their personnel not to assign them unless requested or if necessary.