Loooove my ST2000DL003 HDD. I've had it for for than 2 or 3 months now and no problems with it. I am sitting on SATA 3 Gb/s and not SATA 6 Gb/s, but its plenty fast for me as I only use it as an archive drive and not an OS drive (So yes, SATA 6 Gb/s is backward compatible with 3 Gb/s so you're fine). Speeds I got was around the 50 MB/s average when writing about 70 GB for testing according to HDTune Pro (great HDD tool btw), reads I think are about the 100 MB/s mark. I love this drive so much that I bought another one for the same price at $69.99.
The second Seagate that I bought is residing in a USB 3.0 external case at the moment. Had to get new drivers for my PCIe USB 3.0 card as the ones that came with the CD kept BSODing my computer when connecting and disconnecting the drive.
I also just did a SMART check on my Seagate and its all green, health is all green according to HDTune Pro as well. As for the Samsung drives, my main online retailer, NCIX, currently doesn't carry any Samsung HDDs.
I have used green drives in the past from Western Digital, but I had MASSIVE problems with those bloody things. Here was my thread on the whole issue (I am a member of another forum):
http://forum.xbitlabs.com/viewtopic.php?f=5&t=17913I did do an RMA for my borked drives and got a refurbed/recertified 1.5 TB Green, 500 GB WD Black, and a 1 TB Green. Incidentally, I was running out of space on my C drive so I had to get that 1.5TB Green installed to make room. So far, no problems with it.
All drives do fail at some time, so regular backups are good thing to do. Although, you will be limited by your budget on what backup methods to use. Originally, I was planning to use my older model Seagate 2TB (ST3200542AS) for my anime that I wasn't seeding and use the new Seagate as my backup for those anime. But I was also quickly running out of space on those drive so I had to delete my copies and had to gather my other non-seeding anime that was also on my C and E drives (the E drive is a WD 1TB Black for my seeding, planning to replace that with a 2TB Black when I get around using WD's Loyalty Program to get a discount on that drive) onto the Seagate drives. So right now, I really have not backup plan setup simply because I don't have the cash to get a much larger case (might as well get a 12 drive server chassis and a couple of mini-SAS RAID cards and mini-SAS to SATA fanout cables for the backup plan that I want), more drives, and the additional RAID card that I would need for redundancy. Burning to DVDs (which I used to do a lot in the past) for backups is just impractical for me as well simply because I would have towers of that lying around.
I also had a much older model Seagate at 500 GB which was used in my original system build as the OS drive and never had any problems with that either during its use.
If you want to stay on top on the health of your drives, again, use HDTune Pro. It does testing and benchmarking. You can also use Windows Event Viewer to view HDD errors like bad blocks. There are tons of SMART checking tools out there (HDTune Pro does that as well) so you can check the SMART status of your drive. I just use the ones from the manufacturers and they work fine. They also do various testing on your drives to see if they are stable or not. SeaTools for Seagate and WDLifeGuard for WD drives is what I have in my system right now.
Hope I helped a little!