Originally Posted by
Blacksen
Most guilds gear in this order:
Tanks > DPS > Healers
The core reason healers are last is that it takes an enormous amount of gear to drop a healer in favor of a DPS. For example, we started doing heroic Omnotron and heroic Magmaw with 8 healers (back before all the nerfs). It took us 4-5 weeks before we felt like the healers had enough gear to drop a healer and pick up a DPS.
Healing produces a binary result: sufficient or insufficient. Thus as soon as you have the gear to be "sufficient," you should stop gearing your healers.
In most fights, your tanks take more damage than anyone else during the encounter. Thus giving your tank a marginal upgrade significantly decreases the raid's damage intake. If your tanks take 2% less damage, then that probably means your entire raid is taking 1% less damage.
For DPS, you're also mitigating damage by securing a faster kill. Usually, the bench marks can be very big: skipping a Fued on Chimaeron, or skipping a Golem spawn on Omnotron, or killing the Elementium Monstrosity a bit faster, or skipping Adherents on Cho'gall.
Really, you should gear for the next fight. Most fights are a DPS check, but a few are healer checks. If your next progression boss is Chimaeron or Omnotron, you should gear your healers. If your next progression boss is Nefarian, Maloriak, Cho'gall, or Sinestra, you should gear your DPS.