Interesting find, after Creator's update Fanatec driver had problems recognizing my wheel and when i did get it to recognize it, FPS was impacted. So went ahead and removed driver and then reapplied, FPS went back up. Not saying it's a global fix for everyone but seems that the driver had some issues and I did see an increase in performance booting up now too (2-3 second differential).
Another issue that's common and becoming more evident is that people with performance issues only looked at their Video drivers. Look at ALL drivers, chipset especially, sound, everything, especially if you're one of those folks still on their "upgraded" installation from Win 7/8.
Also verify your drives (SSD's) have latest firmware upgrades (that means you people with Samsung SSD's, you can use their utility to optimize and upgrade firmware, really easy). This has been seen to improve performance for some people with OCZ, Corsair, Samsung, etc. Also make sure windows 10 has been optimizing your drives properly, and if you were using an application similar to Auslogics before or even present, make sure it's updated at least or fully removed if you don't use it more.
Those still on your upgraded installs of Win 7/8, it might be time to reformat and do a clean install of Win 10, you'll benefit the most from boot times and game load times. This comes from removing deprecated drivers left over that maybe causing issues. It's not suggested to use driver cleaning utilities as these are usually loaded with malware or bloatware in free versions. You can use utilities like DISM and other Microsoft utilities to remove deprecated drivers and devices, but in that case it might be easier to reformat.
Another tip is to minimize what's firing up in the background and what applications that have not been updated and verified to work with Windows 10 can cause performance hits. Especially when they are in your start up. After 1511, and even 1607 and 1703, this is becoming more of an issue in terms of performance. Verify your apps and start up items, even if it was compatibile...compatibile is not same as optimized.
Hope this helps as these have been tried and true tips that helped with optimizing AC, ArmA, and a few other games seen to be impacted by performance hits.