I have a problem with this survey. You don't ask what hard drives we have which have not failed.
So if all manufacturer's drives had the same reliability, all you would be measuring is the relative popularity of each make.
I have owned 4 seagate drives; none of which have ever failed, one Samsung drive that was in a PVR and got corrupted too often to use in that way, but is fine in my PC. I had one maxtor drive that slowed down by an order of magnitude but did not actually fail, and I have never owned a WD drive . So how do I fill your survey in ?