SoS - this is a tricky little tool. Looking at last yrs numbers and using that as the SoS rankings - like most places do - is going to be very misleading. Obviously defenses change dramatically from yr to yr.
The best thing to do is use lst yrs numbers as a base and then tweak them accoring to key aquisitions and losses from the offseason. You can then look at each teams schedule given your personal D rankigns and create your own SoS system.
I think ignoring or downplaying SoS is a huge mistake.
Take GB for instance. This is not a knock against GB at all - but looking at there schedule from last yr compared to this yr, and yeah - one could easily come to the conclusion that its gonna be very difficult for GB to put up the same kind of offensive performance in 2005 than they did in 2004. In 2004 the rest of the division was extremely week defensively - either through injury or just lack of talent. This yr CHI, MIN, and DET (even though DET has looked terrible this preseason) - have all gotten better defensively - at least on paper. Add to that the fact they play BAL, PIT, PHI, and CIN this yr instead of IND, TEN, HOU, and JAX - thats just a small sample of the types of things you need to consider when looking at SoS. Just dont ignore this valuable piece of information though.