Lavarnway from the beginning would have been a terrible idea. Ryan Lavarnway grew a lot this year, he wasn't a candidate as a starting catcher in April.
Saltalamacchia is a good catcher, easily average or better among American League catchers. He's not a stud, but he's young and effective, with a strong point to his game for every hole. If he doesn't improve, he's a starting catcher. If he does, he still could become an all-star. On the whole he's fine as long as he doesn't actually regress. If we cut him, you can count on 6-7 teams competing to pick him up and give him at least a platoon role on their squads.
I don't expect him to lead the league in passed balls next year now that he's not likely to catch Wake as often, and without that flaw, there's really not a lot to criticize. You don't expect your catcher to be one of your leading discipline guys, and a catcher who can hit .250, slug over 15 HR's, and throw out a third of baserunners, used to be the gold standard. It's still not that easy to find -- we've been spoiled by Tek for too long to realize this, but Salty's performance this year is pretty much what any team with a hole at catcher (like we had at the beginning of the year) hopes to wind up with when they trade a bit piece for a young project. Which is what we did to bring the kid to Boston.
Far from docking the kid playing time I'm pretty sure the FO is very happy with Salty's return this year. It certainly coulda been a lot worse.