Amazon's new Echo speakers sound better, but do you need to upgrade?

Amazon has new Echo speakers to sell you. And if you're wondering whether or not to ditch the old ones for these, the answer comes down to two key questions for Alexa, the personal assistant. Do I prefer the looks of a round speaker over a cylinder? Do I crave better sound? This year Amazon is all about being spherical, in the shape of its "The Spheres" corporate headquarters in Seattle.