Trying to level my DK a bit faster, and was thinking of dual boxing him.

Question is, of the 2 toons that could be possible playmates, one is a lock, the other is a druid.

Should I go with the mass dps route (DK is unholy, lock spam seed) for mass AOE effect ? (possible down time die to eating/mana issues)
Or go the other way and just have the druid heal him (for less dps but 0 downtime due to healing...)