From my perspective, trailers only show the 'high' spots of film or serial. They are made to attract viewers who probably didn't know the main course was even coming. Like life, many productions are lng periods of routine, spiced with the odd exciting bit.
On another tack, has anyone seen the trailer for series 2 of Vigil? After their stunning success with series one (alleged life on a nuclear submarine) seeing how they portray life on what looks like a UPAS unit might raise a smile or two. However, since the mistress of misery (Surranne Jones) is a main character, don't get your hopes up.