I've been running a LG WH16NS40 Blu-ray drive installed internally on my 5,1 for about 2 months now. And while it works great reading and burning discs, there are some incompatibility issues with system sleep that drives me nuts. The optical drive will disappear when the Mac Pro sleeps. (Currently running El Capitan). Some users on the internet suggest disabling "Put hard disks to sleep when possible" in energy settings but the issue still occurs. A shut down of the Mac down and then a reboot is required for the drive to reappear. There is no firmware update for the drive that I'm aware of since Mac support is non existent. (I'm also speculating that it causes some program and finder crashing when it looks for a drive that doesn't wake up.) I went ahead today and reinstalled the original superdrive and I will run this drive externally. I have an external eSata hard drive dock, so I just need to get an SATA data+power cable and extension to run this thing as a bare drive. Anyone has experiences with third party optical drives on their Mac Pro? Edit: The 2nd optical drive bay is occupied with an auxiliary power supply so I can't install the drive there either.