I never bothered with pets like Shizune or Qlaya or Shasha. They seem ok in pk.. but for quest, their HP seems too low to be really useful. I don't wanna spend entire quest fight to keep reviving a pet who has such low HP.

I use Kanako with my Water Priest tank. My Kanako has 145 CON at lvl 99rb, so she is great as a feeder in quests/15rs etc.