Outside of a few examples customer support on PC parts might as well be non-existent especially with GPUs. I haven't heard too much bad about Sapphire lately though so they might be trying to really improve their image with the enthusiast market.
Every manufacturer will have horror stories like that at some point. The big picture is whether a manufacturer continues to have horror stories or whether they improve and become more consumer friendly. Everything we have seen seems to indicate that the latter is true with Sapphire. Plus their contributions to that Dallas GamExperience thing appeared to be very generous as well.
I have heard way worse complaints about Sapphire verse any other manufacture. I would still go for a XFX 6950 2GB any day over this Sapphire one. I have had nothing, but a good experience with XFX and their double life time warranty helps me sell my past gpus quite easily.