The August firmware updates are meant to improve stability to the operating system and bring performance enhancements to graphics, but no major changes are included. According to the Microsoft Surface update history page:

Surface Pro 3

The Surface Pro 3 gets an update for Intel’s HD Graphics Family driver update (v10.18.15.4256) improves graphics performance and stability on Windows 10.

Surface Pro 2

The second generation of the tablet also gets the HD Graphics Family driver update (v10.18.15.4256) improves graphics performance and stability on Windows 10. Surface 3, Surface 2, Surface RT, and Surface Pro do not receive any new firmware update. The firmware update is rolling out immediately, it will download and install automatically, but you can always go to Settings > Update & security > Windows Update to check for the firmware manually. Source Microsoft (link 1), (link 2) All content on this site is provided with no warranties, express or implied. Use any information at your own risk. Always backup of your device and files before making any changes. Privacy policy info.