Honestly, umbral in an exp zone. You don't need a "raid force" to get any of the gear, apart from zelnithak, doomshade and rumblecrush, and even zelnithak is debatable.
1 exp group can take out just about any mob in this zone. Granted, all of the mobs are basically 53+, but it's a high level zone.
The loot in this zone is great. It allows those guilds that can't or don't do HoT or other high level zones to get reasonably well equipped to be able to do the higher level raid spots.
I think by now that people should realize that a ton of the gear from umbral is situational. (case in point - a range item drops here with +1 to a couple stats and +35sv disease.... ) a cloak with +5 mana, but +10 to fire and magic is great in particular siutations.
From my perspective, this item, as well as many items from umbral don't "absolutely suck".