Wow, great and unexpected news, I think this is a really good signing, especially for our team and our offense: Not only does it give us quality depth at the O-Line, but with all the heavy, unbalanced lines the Niners use, I think having a good reserve swing tackle like Boone is even more important for Niners than it would be for other teams, because they use their reserve lineman so much.
And is it just me, or do those numbers sound extremely reasonable? I mean he got a nice signing bonus, but the salary numbers sound very manageable (although we do not know about incentives) and I would have guessed he might have had a decent chance at getting a bigger contract next year in free agency, since quality linemen are hard to find in the NFL. Think about teams like the Rams or the Bears or the Cardinals (you could even argue about the Seahawks and thus the entire NFC West): I think Boone would have had a shot at being a starter at those teams and he still chose to resign with us. I like it.
But I think I might have the reason why he wanted to stay with the Niners: With most other teams, he would at least be a bad snap away from starting, like he would be with us as the primary backup tackle. But with the Niners, even if both starting tackles stay healthy, Boone will get a fair amount of snaps in the heavy packages and I would guess he took a liking to playing "eligible receiver"