I see you have Stillen Camber Plates in your Sig...Peterson said:Yes. $45 spent on camber bots is much better than spending $100 plus to replace a tire or two.
When you lower a car that does not have equal length upper and lower control arms, the tops of the tires tilt in the further down you go. If you lower the car and don't correct this tilting, then yes, you will wear the tires unevenly.
If you are going for a 2 inch drop, or more, I would definitely recommend getting camber bolts. Some people didn't need them, while lots of others did. I say get them and be confident that your camber is correct.