Hi, Hotgates,
Honorbuddy supports both DX11 and DX9.
However, some graphics driver are not completely compliant with the DX11 spec. They either have bugs, or most of the time, take 'shortcuts' to boost their performance (outside of the WHQL testing). These shortcuts cause problems in real world applications like Honorbuddy. This is why you see us recommending some users go back to DX9.
The best thing to do is try and see if your vendor has done a good job with DX11. If you start having issues, go back to DX9.
cheers,
chinajade