Pros: USB 3.0 speeds and fast access

Cons: These drives can be placed on their side, but I would not recommend it. it's a chance of falling over. Always place it flat.
Drive arms can damage the platters and there is no recovery of data.

Other Thoughts: As a Photographer, I store my captures and video. You can get a lot of images and videos on 6tb.

Pros: Very quick setup: plugged in, waited for PC to recognize it and assign a Drive letter, then used.
Comes with NTI Backup software, but as I already use another product, I did not use. But nice feature to provide with such a large capacity drive.
Backing up files from other drives that were reaching capacity has been a breeze. Transfer speed has been @ twice as fast as had experienced between HDrives before! Really nice considering am planning to move @ 4 TB total from 4 other internal HDrives to this external unit.
Fast and Quiet. Price for size was also very nice.

Cons: None so far.

Other Thoughts: Would recommend this to anyone who has SATA 3 connection; needs lots of space; wants to do backups.

Pros: Drive spins up very quickly compared to other name brands I've used. Doesn't hang OS X finder.

I'm using it with Apple's Time Machine to backup my Mac and it's working great for that.

Cons: While there is no fan noise, you can hear the hard drive when it's under load clicking away. It seems quieter when not being accessed than my other drives. For some, the noise might be annoying.

The design requires the drive to sit down taking up a large rectangle of space on my desk. I wish it was design to sit sideways.

Other Thoughts: This is the only other brand I've found that works somewhat well with Macs. It powers down and doesn't hang when the system reboots.