IMO, there is no debate. If you can fit your entire library onto a 750 bg drive (I can), and then mirror it onto a second drive, you are more secure than futzing with a RAID. The only falldown is keeping your backup drive current. Ideally (for me) this involves at least one additional drive (or set of drives), so that backups can be leapfrogged.
I used an Adaptec 4-port RAID running RAID-0 (striped) on two ports, RAID-1 (mirrored sys drives) on the other two, on my main machine, dating from the age of Nostradamus. As with all things techy, I feel duty-bound to ascertain and experience every screwup imaginable, at least once. So I have personally wiped my RAID clean, twice, in the pursuit of knowledge.
The first time, I was switching out one of the mirrored sys drives and attempting to flush the card-based raid table, so that it would read the new drive as blank and restore to it. Only I flushed the raid tables on ALL the drives, wiping all knowledge of the two striped drives.
Recovering from this was surprisingly "easy", since I had not screwed up anything else on the drives, and had (luckily) elected to use all default settings. The wiped card was able to read the wiped (of RAID info) drive without difficulty, and i was soon up and running, almost as if I had intended to do all that in the first place.
The second time, one of the drives in the striped setup failed, and I experienced mortal pain first-hand. RAID-0 is no backup solution, not that you intended to do that, anyway.
The interesting thing to me was examining the remaining half of the RAID-0, a single drive. A 250 gb WD, half o a 500 gb array, the RAID info resident on the drive still presented the single 250 gb drive to the OS as a 500 gb drive. I think there's something in that for the RAID-recovery software you mentioned looking at, although RAID info was the only coherent info I was ever able to get from the drive. Ultimately I wiped it.
In the old days, a compelling case for RAID was the data access speed. But with 3gbps SATA drives, faster than most old RAIDS, that argument pretty much goes away. Maybe if you are streaming uncompressed HD you need a raid, but short of that, SATA seems perfectly fine, IMO.