I was so pleased with the performance that I will be ordering another one after I submit this review![EDIT: I did buy 2 more, and the read/write speeds were almost the same or slightly better than the first unit. But, please note I changed my header, because I see the current listing is for refurbished drives. The 3 drives I purchased when the listing was for brand new drives.]I bought this drive because I wanted another inexpensive high capacity hard drive for my archival backup drives. I was surprised that it was a faster 7200rpm drive instead of the more common 4800/5400rpm drives.Pros:-- 7200rpm drive (even though the listing didn't say I was going to get such a fast drive). In the attached pic of drive speed test, the largest graphic is for the Avolusion. You will see for sequential writes, it's twice as fast (250MB/s vs 120MB/s) as the 5400/4800 Seagate/WD drives, although I was only expecting a ~33% improvement. We do a lot of archiving/backups, so it's a real time-saver. A sample 4TB transfer finished in half a work day. For comparison, I also included a very speedy SSD (3000MB/s), but that's way too expensive to serve as a backup drive.-- high capacity drive (I got the 12TB version)-- very inexpensive for any speed drive (7200rpm is bonus), <$10/TB-- 2yr warranty-- excellent customer service (initial problem turned out to be a flaky USB port on one of my older laptops, not a problem with Avolusion; but they were quick to provide RMA and paid shipping label when I first inquired)-- very rugged case (really hard, not some cheap plastic), which probably makes it "feel" hotter even though it actually doesn't get as hot as other fan-less drivesNeutral:-- Big, but actually smaller than all my other portable power plug drives. It's about 2x tall and 2x wide as my Seagate Backup Portables or WD MyPassport/Elements pocket drives. Metal base improves heat transfer and makes it rugged, but also heavy. It's perfect for my archiving/backup and then store away. But to carry around when traveling, the Seagates/WD are more practical.-- First few times I ran it, it made some brief "noises" at the beginning. But after using several times, the noises went away and the drive ran relatively quiet. The drive now has 20+ hours on it, and no odd noises.Negatives-- none that I've encounteredIn summary, I got an excellent drive at an excellent price, with excellent response/times from the seller's customer service. Once I hit the submit button, I'll be ordering another one!I want to comment on a few critical reviews posted elsewhere, that I feel are based on misunderstanding of externally powered hard drives or not backed by facts/data:1. Reviewers complained of getting much smaller usable capacity (e.g., 10.9TB for a 12TB for Windows computers). This is misunderstanding of how Windows reports disk usage. Avolusion (like all hard drive vendors) reports capacity in decimal. In Windows, it will show 12000119746560 bytes (which is ~12TB decimal). But Windows follows the old convention and then converts it to TB binary, which yields 10.9TB binary. You can approximate conversion of TB decimal to TB binary by dividing by 1.1. So 12/1.1=10.9. You ARE getting a 12TB decimal (12000000000000 byte) drive, but converting TB binary, you will get 10.9TB binary (which is what Windows displays). Likewise, a 5TB (decimal) drive will come out as 4.54TB (binary) in Windows.2. One reviewer complained that the hard drive kept spinning after computer shut down. Only portable (pocket) drives that rely on USB/bus power will shut down when the computer shuts down. My non-profit organization has owned several dozen external drives over 30 years. About a dozen use power plugs, none of those will shut down by themselves. This has been true since these external drives first came out. That is why we connect it all to a surge protector power strip with master switch, so we can shut off power to all peripherals after we shutdown the computer.3. Reviewers complained the drives ran hot and were noisy. My Avolusion came as a 7200rpm drive, and normally you can expect them to run hotter than 5400rpm drives. It's the inside drive temperature that matters, not external casing temperature. Surprise, when running long sustained transfers (0.5TB-1TB), my 12TB Avolusion actually ran cooler than either my Seagate or WD 5TB portable pocket drives! My Seagate/WD internal drive temp registers past 50C, but my Avolusion never passed 46C. When waiting, the Seagate/WD (5400/4800rpm) were slightly cooler in the 30-40C range, whereas my Avolusion stayed in the 35C-41C range (again, 7200rpm drive). Regarding noise, the pocket drives are very quite because no fan. The Avolusion also has no fan, but it is still quieter than all my other external HDDs that require power plug. My laptop fan is noisier than the Avolusion.4. One reviewer complained they got a used drive inside (1000++ hours), although it worked fine. I didn't check my drive right away, but when I did, it only had 2 hours, which indicates I got a new drive.