"In 'Chainsaw,' I think I had 30 shooting days, for this I had 37 days.  I don't recall there being any real difference other than it was easier to shoot with a well-oiled crew and professionals that had been working and working and working for a lifetime.  I don't know how it changed the style so much as I probably had less coverage shooting this, because it's character dependent.  I think visually my films take on a little different style in everything I do.  I tend to want to reinvent myself, that may be a good thing or a bad thing.  Possibly adapting to the schedule had something to do with it."

- Hooper on the Salem's Lot Warner Home Video Blu-ray Director's Commentary

 
So we can explain the whole Poltergeist thing with a single statement.