Hi. I have a mid 2012 Mac Pro that I leave on 24/7 and need to increase the size of my main drive (Seagate Baracuda 1.5 TB, 1.25 TB full) and have been thinking of either a Seagate Enterprise NAS HDD 3TB or Seagate (non-Enterprise) NAS HDD 3 TB. I got into thinking about this level of drive because I had a main drive failure (Seagate Baracuda 1.5 TB) and one of Seagate's Tech reps helped me and was just amazing and warranty replaced it with a Seagate Enterprise NAS HDD 4TB, which will be my Time Machine drive. So the decisions are: do I go with the Enterprise for approx. $100 more or the non-Enterprise. And then since I'm at 1.25 TB full on my 1.5 TB am I being penny foolish getting a 3TB replacement and should I buy a 4TB. I will need two of whatever I get because I put a mirror drive in Bay 2 and then do a mirror backup to it. So two 4 TB Enterprise drives is a chunk of change. Why Enterprise, for one thing the 5 yr warranty vs 3 yrs with the non Ent. And from what Seagate says, the Enterprise are just that much more solid. Coming from years of using Baracudas, the NAS HDD is a huge jump ahead, I know. Usage: I'm slowing down in my accumulation of programs and data so I don't expect to *need* the extra larger drive because I'm gonna fill it up fast. And a 3TB will at least start me off at 50% full. Of course some of you who really know what you're talking about may not like the Seagate line and point me in an entirely different direction any way. I can't wait to see your replies. Thanks everyone.