How are fans dying from heavy use an indication of manufacturer quality?
Sapphire is like the grand daddy of all of the AMD card makers. They sell the most AMD cards in the entire world and have been making cards since the dawn of AMD time. They also have an R&D role with AMD so their knowledge is second to none. That doesn't mean they don't have defects, but my research indicates they are every bit a top tier manufacturer.
Sapphire also produces the AMD branded FirePro cards, and they also produce every 5970/6990/7990 no matter which manuf actually sells it.