I have a full set of CoF Berserker exotic armor. I replaced the default runes with six Superior Runes of the Pack and noticed that it was +50 Power lower despite having same the power bonuses as the old runes. It seems that set bonus is bugged inactive.
Edit: I noticed that I mysteriously have +50 more Healing Power now (no food buffs). Looks like the set bonus is bugged to add +50 Healing instead of Power.