If you're like me, you probably have multiple PCs with Photos, Music, Video etc. on them.  For me, it's more of a backup strategy- if one HDD fails, I want to have all my media and storage is cheap.  Sure, I could get a Mirra device or similar but a cheap ~$30 solution that works great for me is Smart Sync Pro, a software package that enables me to automatically sync my important documents, photos, music, home videos, and yes, even Recorded TV programs from MCE's around my home network automatically.  It watches network folders for updates to metadata (such as # of times played in WM Player, a feature you can enable in Tools|Options) so when I use Auto Playlists on either of my PCs, I get the same listing of songs.

Setup isn't for the faint of heart but it works great. I have a co-worker who turned me on to it and uses it for complete system backups to an external drive he keeps off-site. Check it out- you get a 30-day evaluation period.