Just be careful - personally I wouldn't want to run a RAID array (regardless of the hardware involved) without a battery backup, especially if it was holding my backup data. Maybe that's being over careful, but I've experienced first hand what a power failure can do to a RAID array and it wasn't pretty.
In general these NAS systems are designed to be left on 24/7 (mine is in a cupboard hidden away!) - if you turn them off, make sure you go through the proper shutdown routine in the web interface.
EDIT: Just a thought - QNAP do a 1 drive NAS enclosure, which you could then backup to any old external USB drive (plugged into the NAS)... that way you avoid the raid/ups but still have a backup of your backup (this is what I do with the 2 drive QNAP 239 anyway)...
Edited by jhurrell (Wed 06-Jul-11 22:23:10)