Healing Turret creates a water field
It is posted on the wiki, has several threads dedicated to it here, is discussed in every cross class combo thread, mentioned in almost very turret thread, and discussed at length is build discussion threads, so I am absolutely baffled as to what you base the assumption that it is not common knowledge.
Poor craftsman blame their tools. Poor players blame their Engineer.
From the small amount of testing I did, picking up the turret will always give you more heal in the long run because it reduces the cooldown. This becomes more and more true the more +boon duration that you have. So only explode the turret if you need that extra bit of health now, or have teammates around who need heals.