Re XFX: Speaking of the DD editions (I've never owned a "Core" model), I like the construction quality, and the materials, like aluminum shrouds instead of cheap plastic. Up to the HD7870 stay relatively quiet too. I haven't yet had one die, and recently sold a HD5770 that was probably at least 3 years old.
Then I got a HD7970. Oops. Noisy fans (including some rattling), very hot-running, and WORST, unresponsive support. The latter in particular is why I got a RMA on it, and will be replacing it with a Gigabyte. While not on my "Do Not Buy" list (it takes outright incompetence, e.g. Diamond, or dishonesty, e.g. CM, to make that list), they will no longer be one of my preferred vendors until I've become aware that their support has improved.