I finally got to spend some time at the DAC show floor on Thursday (which was day four and the last day of the show). It was very quiet, not many people around, and many booths also running with low staffing. However, unlike the Embedded Systems Conference, this last day was not indicative of the show overall.
Talking to the few vendors left standing, Monday and Tuesday had apparently been really good, and Wednesday quite decent. The quality of participants was apparently also good, and the general feeling was that the show floor was useful and exhibiting was worth the expense. So even if traffic is lower than it used to be, it is still very useful. For me as a first-time visitor, it was also striking that the people in the booths were knowledgable techies who you could ask deep questions and get useful answers.