Here is a great survey on PDF preflight, that which many also call postflight, which was introduced in this blog post:

Posted by Marco on Jun 23, 2009 in cPDF
In 2008 Enfocus wanted to find out who exactly their clients were. They held a survey. 4.840 users responded. Now who was using what kind of software and on what platform? Where do they live? What’s their primary business? How frequently do they use PDF-files? Do they even check incoming PDF files? And… what were the errors those files contained? See: http://www.digital-engineer.net/archive/entry/preflighters-around-the-world-this-is-you/

The most common preflight problems with PDF print-jobs.

About half have see their print destined PDF’s failing often and the most common problems are non embedded fonts, low res image usage and RGB color space used. Exactly what the problems were about fifteen years ago (Replace non-embedded fonts with missing fonts.) when Markzware first brought out FlightCheck Professional, which can postflight PDF files from Adobe Acrobat (and other software’s) as well as a range of source or native files like XPress, InDesign, MSPublisher and more. View the full survey results here.

Specials going on FlightCheck- save 20-50%! See:
http://www.markzware.com/promotions/  Read more... (208 words, 1 image, estimated 50 secs reading time)

Question and Answer: FlightCheck Professional and Adobe’s Live Preflight

Here we see an interesting question from a potential buyer in the U.K.:

Hi David,

Yes, it was an interesting demo. However, one question that I have is regarding InDesign CS4.

I have read some of your comments regarding Indesign’s preflighting features compared to Flightcheck, which I totally agree with, but do these comments still stand when comparing against Indesign’s “live preflight” offering – I guess they do but would value your opinion.

Kind Regards,
Ian.

The answer to this very good question was as follows:

Hello Ian,

Excellent question. InDesign CS4’s new “Live Preflight” feature does appear to have some interesting functionality which could be useful. For instance text overflow- and being brought right to the issue to fix it. However we also had our FlightCheck Studio (XT and Plugin offering live preflight) which failed- designers use the other side of the brain when designing and do not want to be bothered, while in the midst of the design. Thus, FlightCheck is like your tennis coach, whom you sit down with after designing and it warns you of hundreds of things- 200 more than InDesign’s Live preflight approximately.  Read more... (540 words, estimated 2:10 mins reading time)