You are basically doing it as a manual RAID 1 system; with frequencies determined by your backup cycle. RAID 1 does it on the fly and up to the second.
I am still quite wary of RAID even with RAID 5 (being the most cost effective). Data recovery on raid arrays can get horrendously expensive or so I heard. Even normal data recovery costs thousands (although I was lucky to know a vendor who charged me only 700 bucks for recovery last time).