3.5l Ecoboost V6 had one timing chain from 2007 thru 2016
In 2017 it was changed to 2 timing chains, one for each bank of the engine
More durable than what???
Later models of the same engine "should be" better than previous versions, but..............only time will tell
3 years is not really long enough if you are comparing the 2007 design to the 2017 design, IMO