Well, I play noct astro, and I find that extending lightspeed and the Aether thingy at the same time with uh.. the stun move (My brain goes blank when reading astro move names...) helps, also upgrading retrogradation to shorten it's cooldown is useful, it does an aoe esuna, AND removes beneficial effects on the enemy party, it's funny seeing the other healer almost die and pop attunement, only for me to rip that attunement off
4v4 noct is better, but I find that diurnal sect is excellent in 8v8. :3 when I team up with my whm friend, we both end up doing 900k healing, nobody dying (save one or 2 to a melee lb) and just jumping around the map as our HoTs do all the work.