i have a raid 5 with 4 300gb drives, and today one of them freaked out for a second because of some kind of power issue. the drive said it's damaged, and my raid status was "dead", not "degraded", as it normally does when one drive fails and you should replace it. I was frightened. The moral of the story here is that YOU SHOULD ALWAYS BACKUP YOUR DATA NO MATTER WHAT.
So if you actually notice a good performance increase, like if you play a lot of HD intensive games or do a lot of compiling stick with your RAID 0, just be sure to backup your data and you have nothing to worry about. You can make a RAID 5 if you have 3 drives, but that has SIGNIFICANTLY lower performance than a single drive, let alone your super fast RAID 0.