Alexa is no longer "new." The smart-tech revolution is now in full swing, and Amazon Echo is at the heart of it. According to Edison Research, nearly 40 million people own voice-activated speakers, which is about one in six U.S. adults. Echo changed the game, and millions of households have integrated Alexa into their daily lives. For many technophiles, it's not a question of whether to invest in smart technology, but what kind.