In my experience, totally worth it. I was shopping for an Edge Sport and was going to get a 2015 until I actually used Sync 3 - I waited on the 2016 in large part due to Sync 3 and couldn't be happier.
The Sync 3 system is far more responsive; it has a capacitive touch screen instead of a resistive touch screen, meaning that it can take multiple "inputs" at the same time. This allows for things like pinch-to-zoom on the map in addition to the added sensitivity and responsiveness.
Additionally, the Sync 3 system is going to last you longer - perhaps more important if you're purchasing than if you're leasing. Carplay/Android Auto are coming to Sync 3 later this year, which is nice.