Beijing and London had some pretty crafty opening ceremonies.
Beijing is the all time winner. It was amazing, the visuals, the culture. It was a game changer.
London's was heavy in budget but felt like a history lesson. On the other hand, the closing ceremony in London slayed(and it's usually a non-event)
Rio's games have been plagued with controversy and budget issues. But there's no question Brazil has a very broad culture, nice music and colorful traditions.
And PLEASE do not try to measure what will look like by watching our World Cup opening in 2014 because those usually suck. I remember the opening of our Pan American games in 2007 and they are great, I don't know if it's on Youtube.
If the situation in Brazil and the lack of preparedness for the actual games are any indication, then no the Rio opening ceremony will not slay. I predict it to be a mess just like everything else in the Rio Olympics has been so far.