+Karma, Gerox >w>
Another thing to take into consideration is how much you like the grass feature on LastMoon. I love to have it with complete thickness and distance, but even on a newer computer it will crash the game running in Directx. OpenGL works perfectly fine for that.
A random funfact about OpenGL is that it causes a glitch with presets that gives them hillbilly teeth. If you've got a preset or a friend with one, that might affect you.
Just try them both. It's not gonna cause any harm to sample. ^^