Yes, the rather large company I work for has seen failures. To be frank I don't have very good results with Blue Label Western Digital Drives. Which seems to be the drives of choice on the ED800 G1. Here are the tests we have done to try and get this machine to stabilize.
Using AHCI instead of IDE emulation, replacing the Western Digital drives with (New) Seagate drives, make sure to disable the Sata Power Option in the BIOS and finally making sure that UEFI drives and Legacy drives listed are in the correct order. I have noticed that by default on some G1 machines in legacy the drives are listed Drive 1 and then Drive 0.
We tracked the problem machines down to one pallet of ED G1. So, I don't think it has been 5% however, it has still been an irritation. Interestingly enough the primary drive reports problems and then the drive will disappear or the problems at that point begin to occur on the secondary drive and the secondary dissappears.
Sometimes, I can right click on Computer and go to manage / disk management / More Actions / and Refresh or Rescan the drives and the missing drive(s) reappear for a few hours to a few days. After all that we have done I still have approximately 6 machines no longer under warranty that continue to manifest this strange behavior.