You know that WD RED is recommended by major NAS vendors and it boasts a lower MTBF and longer warranties, but technically how different is RED compared to Desktop drives ?
Well, there are 2 aspects in which they behave differently making them ideal for NAS environment.
TLER Time : ( Time Limited Error Recovery)
If the drive can't write or read the data, it will try to relocate the data. TLER defines how long does it keep doing so before an error message is generated . Now if the drive keeps doing it for a long time, the RAID controller in your NAS unit may think that the drive is non responsive and will drop it from the RAID. Using a desktop drive in RAID would sometime drop the drive when there is nothing wrong with it actually and later start showing it back online.
In short, a lower TLER is good. TLER should at least be same ( or lower) than the NAS RAID timeout. WD Red has a lower TLER compared to Desktop drives, which is good
Less head Parking
What does your desktop drive do when it's in power save mode ? It parks the head away from the platter. When a read/write request is sent to the drive, the Head moves to the platter for read/write. Since it's a physical operation, more head parking and loading means more wear and tear
In Short , the less the head parks, the better it is. WD RED doesn't park the head, which is good.
There are other features like NasWare Firmware, Active 3D balance for less vibration and longer warranties and support, but above 2 features alone should be enough for technical users to consider WD RED over Desktop drives in NAS environment. At a little more premium compared to Desktop drives, they should be your preferred drive of choice for your NAS. If you are looking at even more reliability, look at Enterprise grade drives like WD RE.