Just one week after the official release, about 5.3 percent of Windows 10 PCs are already running the Fall Creators Update. The majority of Windows 10 PCs (74.6 percent) are still using Creators Update, and about 17.3 percent are still sticking with the more than one-year old Anniversary Update.
Anecdotally, Fall Creators Update is up to a more aggressive start than its predecessor. However, we will have to reserve judgment until next month to see if this isn't just the optics of the first few days.
Another notable fact is that Anniversary Update got to over 92% in usage share by the time Creators Update was released. Creators Update got to about 75% only. Time will tell if Anniversary Update loses it's share quickly enough to keep the Windows 10 ecosystem in N + N-1 version state, as it was envisioned.