My experience. Getting rid of Power4Gear and making sure that none of the power saving functions allowed the machine to hibernate got rid of my hard reboot problem. I never did have issues with my system slowing down on a hard reboot so can't help ...
If I remember correctly, and search the forums to verify for yourself, a Bios upgrade resolved this issue for many. If you have not done this yet, that would be my suggestion.
I know this will not help with your issue but just to give an example. WOW is my main game of choice and it is not too graphically demanding unless playing on ultra settings. In ultra I usually am over 60 fps all the time on the JH but when only us...
How about other games? Any issues there? Could there be something in the power plan setting that is not allowing you to use everything even while plugged in? I uninstalled Power4Gear and Splendid to keep those from interfering and changing setting...
Is your laptop plugged in - many forum posts (and personal experience) that the ROG's need to be plugged in for full GPU performance. Battery can't handle the GPU's, drain to quickly supposedly.