I now have both the 500GB version of this, and the 1 Terabyte.
I use this to back up 2 laptops, 1 desktop, and a PS3.
Note: The disk comes formatted as NTFS. You will need a FAT partition to backup your PS3 to, and if the disk on the PS3 is larger than 32GB (very likely) then you will probably struggle to format a partition of sufficient size to backup a PS3 using XP or Vista (even using command line). Try using a free app called SwissKnife. This will do the trick. Presto - one lovely FAT partition for PS3 Backup.
Disks power down when the PC they are attached to is switched off.
The half terabyte of mine is now in constant use as storage and doing a grand job.
Good Disks, from a known name, for a good price.