Are trade shows worthwhile?

The International Safety Equipment Association has sent a survey to all its members asking whether they believe the industry trade shows are worthwhile. See article here

The ISEA is U.S.-based but is this an idea for your trade association? It would doubtless interest us all to know what colleagues in our industry think, not just about shows in general, but which specific shows work best; which show organisers do the best job and, crucially, which shows to avoid.