Any experiences with this new driver? Boinc impact?

Long boring discussing on changes in cpu usage for gpugrid with a recent nvidia beta driver, but at the end this comment has peaked my interest :
"Hello: In Windows 8.1 since I installed the latest Nvidia driver (a couple of days) 334.89 behaves like Linux, (for some time now) the CPU load is reduced to 10-20% (varies according to the task type) instead of 100% previously.

The overall performance of the GPU hardly altered and the change improves load / performance / consumption ratio."

Full forum thread http://www.gpugrid.net/forum_thread.php?id=3615

I will installing to Sunday and testing it out. No choice really, it adds support for the Titan Blac

From the release notes:
NVIDIA PhysX System Software - version 9.13.1220
  • NVIDIA GPU PhysX acceleration is available only on systems with GeForce 8-series and later GPUs with a minimum of 256 MB dedicated graphics memory.
  • NVIDIA GPU PhysX acceleration is not available if there is a non-NVIDIA graphics processor in the system, even if it is not used for rendering.

I didn't know that, I was planning on moving a r9 280x out of this pc and making it all NVidia again anyway.