Whilst this quest was always moderately challenging, the Mod 9 changes - the Con damage nerf, dungeon scaling and some apparent changes in Sor'jek's AI - have made this quest much tougher. On normal, it's tougher than any of the level 19 quests - in fact I'd say it's tougher than the two short level 19 quests are on elite.
I suggest dropping the HP of the giants by 30%, and raising the quest level to 18. Leave everything else as-is (it's good that Sor'jek is no longer a pushover).
Also, this quest should get the same "Extreme Difficulty Dungeon" warning that Devil Assault has.