I voted for Dawson because it just seems likely that by the end of the season the extra field goals that Dawson will make this year that Akers would have missed could easily make the difference in winning the division or not, home field advantage through the playoffs and maybe even winning the Super Bowl itself. After Dawson, I think Boldin will have the biggest impact (especially with Crabtree out), followed by Patton.
I wouldn't be surprised if Vance McDonald has as big or a bigger impact than Patton, though. Here's hoping they both blow the doors off.
It's possible Reid will have lots of interceptions and be a beast on pass coverage, in which case he could have a bigger impact than Goldson had, but that seems unlikely. I'll be ecstatic if he is nearly as good this year as Goldson was last year. I'd hate to see him make an "impact" in the negative sense because his performance is a big falloff from Goldson's - but I don't see any reason to think that will happen.
[ Edited by 49erphan on Sep 1, 2013 at 8:26 AM ]