The major problem with with change and redeposit fees, is that they're largely because the airline doesn't release awards that fit most people. We've become accustomed to grabbing an award when even one or two segments are right.
You want biz, but only coach is available. Book it. Biz opens on one leg. Book it. Biz opens up on the first leg, a day off. You book it. Finally 2 weeks before the trip the right day opens and you book it.
Just being able to use your miles is an ordeal sometimes. I've spent 5 hours on the phone with the friendly NW elite folk in the last couple of weeks tweaking, or finding *some* routing that works. I'm pretty flexible on dates, but awards, in particular FC or Biz awards, are mighty hard to find!