I've attended just one where I saw Vitalik Buterin and it was a great experience. Though I encountered that he spoke more about his smart contracts and Ethereum instead of talking about Bitcoin and the Blockchain technology. It was my bad as I am not good at technical part and that's what was discussed mostly. CES was missed by me and I have been watching videos uploaded by users who gathered there, such an innovative event with the world's leading tech giants representing their skills through their works.