There is a new article online over at it-enquirer.com, which goes into some interesting details about why, how and which preflight tool should or could be used and where within your workflow. In part it says,

“Markzware has been developing FlightCheck for years, in several formats –including a highly efficient and successful online service– to accommodate for printed output, checking for trapping errors and compliance with standards such as PDF/X, for example. FlightCheck can be deployed early in the publishing process, which theoretically saves money as errors are discovered earlier and can be corrected before they cause trouble at the printing press.”
SOURCE: http://www.it-enquirer.com/main/ite/more/preflighting/