Except you're forgetting Nourish and Living Seed. Not to mention the potential for Rejuv to go to overheal is incredibly high. In addition, the mana cost of rejuv in significantly limiting even as you gain additional gear. Throwing out a random rejuv to "top someone up" is a waste of mana and will almost definitely result in a large amount of overhealing. Notable exception would be on fights like Garalon or any other constant pulsing fight. Attempting to follow Blizzard's idea of "small fast expensive", "slow big expensive", and "slow small cheap" really works. Completely forgetting you have Living Seed or Nourish is a massive mistake any resto druid can make. Blindly mashing Wild Growth and spamming Efflo when it isn't necessary is the mark of bad players in my opinion.