San Francisco 49ers Key additions: S Dashon Goldson (franchised), QB Alex Smith (re-sign), CB Carlos Rogers (re-sign), WR Mario Manningham, LB Ahmad Brooks (re-sign), WR Randy Moss, RB Brandon Jacobs, QB Josh Johnson, CB Perrish Cox, WR Ted Ginn (re-sign), LB Tavares Gooden (re-sign) Key losses: CB Shawntae Spencer, WR Josh Morgan, C Adam Snyder Analysis: The 49ers are returning the league's best defense intact, even though they had a few prominent players' contracts expire. While they flirted with Peyton Manning (and to me, this is where Manning should have chosen to play), they have significantly improved their offense since the NFC Championship Game. What is curious is that while San Francisco clearly made a massive effort to improve the verticality of its offense with the additions of Moss and Manningham and even the re-signing of Ginn, Smith really isn't an adept downfield passer. Still, the new perimeter speed should open up room for the rest of San Francisco's offense while allowing Jim Harbaugh to utilize more multiple-receiver sets, which obviously is the direction offense in the NFL has gone. It also wouldn't shock me if Colin Kaepernick -- and his huge arm -- finds his way behind center before long. Grade: A ________________________________________________ Also: Rams and Seahawks got A's (only other teams with A's) and the Cardinals got the lowest grade, a D