It looks like there are no guarantees with border bounces either. There are reports on here of people being grilled and asked for stuff that they never had to show when getting their DTV. That being said it appears that the chances of issue free re-entry into Thailand on a DTV are better with border bounce vs. extension. I just want to stress that it's not completely issue free. :)
I always give my DTV printout along with passport and boarding pass. However you would think that as soon as they scan your passport their screen should show your current visa status?