Spindles of CDs/DVDs are all very well, but it's nice to have stuff more immediately accessible — especially an MP3 collection of everything you own on CD. So, since I've finally hooked the computer up to an amp for music and had some Amazon vouchers from surveys I'd filled in, I bit the bullet now rather than later... expect drives to come down even more in price by the end of the year, knowing my luck.
The first thing you need to understand when buying storage is that harddrive manufacturers are lying bastards: a drive marked '500Gb' isn't, it's 465Gb. A gigabyte is 1024 megabytes — just like a megabyte is 1024 kilobytes and a kilobyte is 1024 bytes — but harddrive manufacturers sell a gigabyte as 1000 megabytes. Then you lose a bit more for the file allocation tables on the drive, the underlying data structure that allow you to put files onto the device. Not very much, and this at least is understandable, rather than the industry making them being deceptive mercenary scum.
Anyway, the Elements series are marketed in 250Gb/320Gb/400Gb/500Gb capacities, minus the missing gigabytes on each. Drives in this series are WD Caviar models, which have a good track record. I think (but check this if bothers you) that they come with 16 MB Cache and operate at 7200 RPM... although over USB2 the drive isn't really going to be pushed when copying stuff onto it, only when seeking to retrieve data. Getting data onto the drive isn't particularly quick, maybe 15-30 minutes for a DVD of files depending on whether they're lots of small files or a few big ones. By this point we're beyond the old IDE standard for harddrives, and if you're looking to open the case at any point and put the drive into a system you need to make sure the motherboard supports SATA.
Physically the enclosure is fairly attractive brushed aluminium, capped at each end with rubberised plastic to cushion slight impacts — it's still a really bad idea to drop the drive, of course. Another thing to watch out for is that the metal case acts as a heatsink (no fan is attached and the power supply is external) and with intensive writing the case gets extremely warm... which is doing its job, but make sure the temperature of the room and positioning of the device allows heat to dissipate. When idle, the drive eventually cools to below room temperature and spins down. Being a no-frills device, there's no supplied management software, on/off switch or stand to allow the drive to stand vertically... but I wouldn't recommend putting a drive on its side anyway... although they're designed to minimise the effect these days, the drive still contains moving components. To keep heat down further and let air move underneath, I've sticky-fixered blocks of cork onto the corners.
The drives are supplied formatted as single FAT32 partitions so that they're compatible out of the box with older versions of Windows, Macs and all Linux distros. Storage this big benefits from another format such as NTFS for storing lots of smaller files, and you may decide to partition yours. Like I say, no software for management is supplied, but utlities such as Paragon Partition Manager 8 have often been given away on Computer Shopper cover discs. (If you partition, be aware that drive letters may not automatically be allocated to the new partitions... in 2000/XP you need to right-click on My Computer, choose Manage, and fiddle under Disk Management. Partitioning isn't needed when using NTFS — but you may choose to do so in order to keep frequently-accessed files near to the start of the drive, or to encrypt a partition with a third-party solution such as Truecrypt.)
The most important thing to remember is that a backup isn't a backup if the data is only in one place. It's still advisable to burn things you want to keep onto CD/DVD before deleting them from your primary drive, in addition to using an external harddrive. It's also advisable to check those CD/DVDs every so often, as optical media can degrade badly in just a few years if you're unlucky.
All-in-all, I'll be pretty happy as long as the device keeps working and is reliable.