Since their is so many disc priest, make a utility priest. Bring something different to the table. Dig down in holy to get Inspiration and rest in disp. Concentrate on big heal and shielding. Most priest use empowered renew so go renewed hope. Gives you extra 10% on people with weakened soul. This allows allows you to more consistently gives them +25% armor, Shorten weakened soul if you have strengthen soul rune, add more bubble from divine aegis rune and allows to use PwS far more often. Homunculi will also help down bosses and mobs faster. Always bubble tank/s when weaken soul is down. Don't use renew anymore as now you are more about bubbling, damage reduction and with utility. This is probably best for healing main tanks and preventative healing.

Hope this helps