Welcome to Librarium Online!
I just dropped a unit out of one my lists and have enough points to give my two Sniperfexes either Bonded Exoskeleton or Extended Carapace? I'm thinking Extended Carapace because the extra toughness from Bonded Exoskeleton won't matter against the plethra of strength 4 weapons (*cough* marines *cough*).
"The internet perceives censorship as damage, and routes around it."
Neither, give it reinforced chitin.
I agree, extended carapace is good if your facing missle launchers, and bond exoskeleton if your facing a lot of psycannons/heavy bolters. But if your just worried about bolters take reinforced chitin, it helps a lot.
Legion Of Everblight: Abyslonia
Protectorate of Menoth: Grand Exemplar Kreoss
I think extended carapace. It will be very good at deflecting those few weak hits that wound. It is more expensive but it is worth it. Extended carapace is the best all-round defensive biomorph for Carnifex's.
Definitely extended carapace. You did say it was for a sniper-fex, right? If you're worried about low AP weapons denying the 2+ save, just park the fex in cover.
"It takes a vast amount of self control to be this dangerous."
---Ogvai Ogvai Helmshrot, Jarl of Tra, VI Legion Astartes