Phototoxin
Explorer
Just wondering if some more experienced players (I tend to DM) could chime in - basically I'm wondering if the +2AC bonus and less damage is better since he's a defender and thus values AC anyway?
I agree with the comments in this thread, but this bears elaborating. If a monster were just faced with a plain mark, this would be the conclusion of a tactical consideration. But in addition to the penalty, the enemy violating the mark also takes damage and heals the target ally. This makes attacking the paladin a better tactical choice even if the attack is a bit less likely to connect. And that makes high defenses worthwhile.A paladin want to get attacked, so making your AC too high can discourage attacks against you (if paladin AC > friend AC +2).
Regarding the "More Damage vs More Armor" thing. I personally would ask the DM how he handles Marks ingame. Does he just abides to them or does he actively break them or anything in between.