My server's in the spare room, so the noise penalty means more to me. I figure that I'll be upgrading the disk well before the few years is up (I double my storage capacity about every 2-3 years). With regular backups (which, admittedly, I'm still struggling a bit with), I'm not that fussed about dead disks. If I was worried about uptime and high availability, my priorities would be different, but going without my server for a couple of days is do-able.