A friend just got dual spec. for her Level 40 Shaman. She had been enhancement spec. for soloing and leveling. Now she's adding a resto spec for work with groups.
She's asking about the trade offs between using a shield vs. an offhand weapon (obviously when she in her enhancement spec). To me it seems obvious that she should be in her resto spec. when healing, and only be in enhancement when tanking or doing DPS. It also seems obvious that she should use a shield any time she's tanking (unless she has a really good item for her offhand that somehow beats out the damage mitigation from all that extra armor).
Now she's asking about how that relates to her dodge/parry talents. (Does the average frequency of dodging/parrying mitigate as much or more damage than the extra armor from a shield? Does the second weapon improve or affect dodge/parry at all? Does a shield offer benefits to dodge/parry? (Is that what the "blocking" factor is)?
I suggested she just go solo a few mobs that are about 3 levels higher than her … say 10 with the shield and 10 with dual weapons. Then review her combat log and figure out the benefits from that. I think she'd be able to feel the difference without even doing any mathematic analysis.
Best Answer
Enhancement Shamans are designed to dual-wield for maximum damage. If you aren't using an offhand weapon, you won't be getting your full damage output.
The fundamental truth is that if you're looking to take the least damage, don't go with the shield -- you'll take less damage overall if you kill things faster. Less damage done means more hits taken, which means the armor bonus of the shield is moot, as you take approximately the same damage either way.
And I hope she's not trying to level on mobs 3 levels higher than her. Stick with yellow or green mobs -- they're easier, you miss them less, and, again, you'll net higher xp/hour because you'll kill them faster than you would the orange mobs.