11 yrs, $5.27M cap hit, takes him to age 37. Not a great signing, in my opinion. First, I'm not a fan of contracts that end between age 35 and 38. They're long enough to make you uncomfortable and worried about a player's decline but not long enough to bring down the cap hit significantly. To me, Carter will be a 35G, 35A kind of guy whose value on a 5-6 yr deal is probably about $5.5M, so the Flyers didn't get much cap relief by extending the length of his contract.
I think the Flyers did a great job with Giroux's contract, but I think they would have been better served by signing Carter to a short deal and trading him at some point in the next three years. Carter is their fourth-best forward and sixth-best player, in my estimation, and this type of contract should be reserved for one of your top-three players.