I've been thinking about running a RAID setup for a long time. Each time I upgrade my hard drive, disk failure becomes more scary. While building my new PC, I finally came to my senses.
Ever since my media collection grew past a few gigs, the thought of losing it has worried me. It's taken a lot of time to accumulate this stuff, after all! A RAID-1 (or even better, RAID-5) setup would eliminate all my worries, wouldn't it?
Not exactly. My collection would survive a drive failure, but I would still be hosed in case of fire.
There's also the issue of waste. Not only does it cost a lot of money to mirror a giant drive (and even more to build an array big enough for RAID-5), but I wouldn't even get to USE it all. I'd miss all those mirrored/parity bits! There's also the additional power consumption to consider.
In truth, my data is pretty static. There's a lot of it, but I don't need to be backing it up constantly. My current back up procedure is admittedly low tech: when I get a new drive, I copy over from the old drive and place it in a fireproof safe. If I'm honest with myself (and not just pining for technology-for-technology's-sake), this is really all I need.