For those wondering about performance by switching here you go - seems about right from what  I have noticed in P3D

 

http://www.guru3d.com/articles_pages/windows_8_1_vs_10_graphics_performance_review,6.html

Yep, the few people that have upgraded to Win 10 confirm these results. basically they can be accounted for with a change to the video driver. DX12 might help a bit, but that remains to be seen in P3d versions 3.0 and 4.0.