If you win... yes you get the division title and get to host a playoff game (against the defending champion Saints).
However... an 8-8 or 7-9 playoff team really loses longterm in my eyes. Come April (should there be a NFL Draft)... you will end up slotted with the 12 playoff teams... meaning there are 2 10-6 teams (TB, NYG)... 1 9-7 (SD)... and for Seattle, who would pick with playoff teams as a 7-9, 2 8-8 teams (JAX, OAK). That's potentially 3 to 5 draft spots lost by making the playoffs for the NFC West winner, who will at best be .500.
Do you want the title and playoff berth and maybe miss out on a player you want to a team you should be drafting in front of in the draft or want to miss the playoffs to maybe get that player?
I ask this question b/c on our game broadcast today Jim (I think it was Jim anyway) mentioned that Seattle media asked fans whether they wanted win and playoffs or loss and draft position and Jim said it was overwhelmingly loss and draft position.