DX10 doesn't have any issues at all, it works faaaar better than DX9, you can fly with 30 FPS over very dense sceneries, the thing that you can't do with DX9.
It needs some tweaks to work well, just like DX9
The only bad thing in DX10 is some products not working with it, like Aerosoft. And this is because of YOU, people like you who don't want to accept the reality, the futur, it's because of developpers who simply don't want to convert their textures to DX10 compatible.