It's not really a question of preferences, it's using the right tool for the right job. Why pay big bucks for a high end video board, then use a rendering engine that bypasses all the neat chips and doodads you paid the big bucks for?

Sort of like buying a Lexus, then continuing to drive the beat up Honda so as not to get the Lexus dirty.. ya know?

Besides, OpenGL is open source, so has the same level of support and reliability as Linux does. DirectX is owned by MS.. support? heh.. The word reliable wouldn't go near it until version 6 or so..