I've started playing a cleric tank a little bit more. I'm liking the soloability and of course the ability to tank an instance. I've only done the first instance "Iron Tomb" on my cleric, but other than being a little squishy for the second half trash I've been going ok. I like that I've been through the dungeon as DPS first, no responsibility other than pew pew and learning the instance. Now that I have the responsibility of being the tank it's not so stressful.
The cleric Justicar soul gives you all the tools to tank, it works and IMO it works very well. My other souls are the melee DPS cleric souls of Shaman and Druid, some of their early tree abilities benefit a tank with some endurance and damage reduction. About halfway up the tree there are a number of abilities that help with block or give you an ability when wielding a shield. From what I've seen the benefit to using the shield doesn't seem to outweigh the additional DPS, though perhaps when instancing the loss in DPS wouldn't hurt as much.
Cleric shields don't get as much armor or tanking stats as Warrior shields, they are also missing the spellpower that you would get in other caster off-hands. It just seems that using a shield as a cleric is a net loss compared to other options. Currently my tree is avoiding the shield talents and I just whip around a staff catching up to 5 mobs in my path with "Even Justice". I've made sure to have the pure damage reduction 3% per point spent in the Justicar and the 3% for 3 points in Shaman. Perhaps when my cleric gets to Deepstrike Mine I'll experiment with a different role using the shield and get some feedback from the healer to my survivability and from the DPS regarding my aggro control.
Has anyone else seen any discussions regarding this point?
P.S. Vacation for me starts tomorrow, I'm going away so updates or comments may be sparse for a week or so.