User blog comment:V3hemenc3/Another support champ idea: Yordle Nurse!/@comment-175.139.36.224-20111106135918

Your heal is just massive because of that AP ratio and cooldown scaling. While you might have thought a 0.2 ratio may seem small, it's effectively 0.8 since it lasts for 4 seconds and can be up every 8 seconds. Compare with Janna's ult as she heals for just slightly more with a 2 min cooldown.

With max CDR, that W has a cool down of 4.5 seconds. I think you need to flatten the cooldown and nerf the heal at higher levels. (Without any AP, you're healing up to a total of 2000 HP over 4 seconds if your whole team is nearby)