Although Kap did appear to provide a spark to certain player(s), (Crabtree), and maybe even a portion of a fan base, he really didn't do a whole lot for the team in terms of improving the output. Points per game, yards per game, passing yards per game, rushing yards per game, wins... all very similar. Just a different way of getting those things. Just for varification, here are the numbers:
Now I am not saying Smith is going to be the end-all-be-all QB this franchise is looking for, but it is not like the 49ers benched Tyler Palko (Smith) and upgraded to John Elway (Kap) last season, and their fortunes suddenly took a turn for the better. Things were pretty good to begin with.