The Nexus 5X fingerprint sensor is faster than the iPhone 6S TouchID sensor. That of course doesn't mean that Apple's sensor is slow, it means its slower than Nexus 5X
SuperSaf TV has put a video on YouTube in which they compare two phones side by side to see which sensor is superior.
You can watch this video here.
It turns out that the Nexus 5X sensor is noticably faster. The new Nexus phones include the Nexus Imprint - sensor working within 600 ms.