I have 2 Raid10 setups. Both have 8 3tb drives, 4 drives would have to fail (2 in each half) at the same time to loose data. Even if half the system had a catastrophic failure my data would be in tact. You do cut stage capacity in half but IMHO it is well worth it. The setup cost about the same as a good cartridge or a set of cables. I store both movies and audio. Will be adding another shortly as Blue Rays take lots of space.
External drives
I'm pretty new to PC audio. I'm using a mac mini as server and have begun to import my cds. I'm getting the impression that drives are not created equal. I've been using a Samsung. Should I wait until I get a 'better' drive before ripping any more music with the theory that playback will be better with another/better drive? I'm thinking that I'll buy a Plextor for $85.00. Thanks for your comments.