I've heard from a number of PC users who've proactively downloaded or had the update pushed to them within the first day or two of availability -- which is noticeably faster than what happened with the original Windows 10 Creators Update that started rolling out in April 2017. I, myself, had the Fall Creators Update (1709, or Build 16299.15) pushed to the HP Spectre 13-inch device I am using the first day it was available. It took months for the Creators Update to be pushed to me on the same device.
When I asked Microsoft last week how long the company expected the Fall Creators Update rollout to take, a spokesperson sent me this statement: "The Creators Update will roll out in a measured way based on feedback."
The reason it feels as though more users are getting this feature update faster is because Microsoft "increased the number of Windows 10 devices we've tested in advance with our OEM device and ISV app partners," according to today's blog post.
Windows 10 for PCs has been rolling out via Windows Update, MSDN and the Volume Licensing Center, as is Windows 10 IoT Core for ARM32, x86, x64, and Windows Server 1709.