From what I've been picking up from reading about him is that he's more a SS than a FS and struggles when asked to act like a FS. The upside is he's a good tackler and very assignment sure which fits with Pettine's D (sending guys after the QB and trusting your secondary).
Pretty funny, because the knock on him coming out of college was that he was a finesse athlete with horrible play against the run. Makes you respect him all that much more that he worked real hard on his weaknesses, apparently.
Anyway, I don't mind this at all. Makes him even better for all 3 downs. You just have him at safety on 1st and 2nd down and slide him down to ILB on 3rd/passing downs. That'd help our defense in so many ways.
Firstly you get Martinez and/or Ryan off the field, consistently, on passing downs. Coverage from our LBs has been a sore spot for years. I mean, a fanbase that rejoiced because of Brandon Chillar's coverage skills has had quite a drought.
Secondly, you can get more of a rotation going at both the LB and S spot. Helps keep your players fresh for when it matters most.
Thirdly, he's just solid all-around. He doesn't have a glaring weakness, so he won't constantly be thrown at when lining up against WRs in zone on 1st and 2nd and won't be completely overrun on a 3rd against RBs/TEs.
I know using a safety at LB is pretty commonplace now, but finding a player who can actually perform in both roles is pretty hard. I think we just found one for the next couple of years.