My current Time Machine drive connected to my iMac has died (my second one to die in 6 years, first one WD, second one Seagate). Ironically, so far it's been my TM drives that need replacing, as opposed to me ever needing to use TM for a failed Mac. Is there any reason to buy a a WD/Seagate external drive instead of buying an internal HD and putting it in a cheap enclosure other than price? Pre-configured externals tend to have software pre-installed, and strange firmwares installed (like parking the drive too often). Internal HDs are slightly more expensive than pre-configured external solutions, but tend to have longer warranties, and I imagine them being slightly higher quality and lasting a little bit longer. Am I wrong in thinking this? What factors do I need to consider? I've always gone for 7200 RPM drives, but I figure 5400RPM should be fine for Time Machine, right?