The Rams D matches up well with SF and Seattle because of our speed on D. The speed (and depth) at DE can force the running QBs back inside, fast LBs (esp when Dunbar comes back and with Ogletree) prevent some big running plays and having two agressive corner who support the run is huge. I could see every team in the division with a split record this year 4-2, 3-3, 2-4....its going to be a tough, fun year in the NFC West.
The need for speed on D is one reason I could see the Rams keeps the young DE (name escapes me) to add more pure speed to the front seven.