Avoid spell speed as much as possible. Always max out crit. Whether you meld Det/Dhit/Piety is based on your preferences, but all healers like to avoid Spell Speed, pretty much. It reduces your mana efficiency and they're the only role really impacted by that. Piety isn't that great either but it can be okay to have in certain situations that stress your MP more than others (such as res spam in 24mans).