The reason why I have little faith in the benefits of RAID0 is because for the cost of the drives and controller, Purchase more RAM and/or a higher speed CPU! There are speed improvements but they were neglible and RAM/CPU improvements are more tangible and effect the whole system not just i/o.
It wasn't a case of anything seeming much faster than a standard drive. The potential for data loss is not to be ignored either, that and the time/cost of keeping your data safe. I've had RAID0 fail due to PSU problems and you wouldn't even know that the psu was the cause from the symptoms either.
The areas of improvement are in specific situations which YOU don't necessarily practice. Also, If you see a boot-up increase of 5 seconds over non-raid and you boot 3 times a week... 15 seconds... so what?
Anyway, the data crunchers that I've set up at work with and without RAID, there's been small speed improvements with RAID) but nothing worth bothering about.
This is a good article here
. I'd call this the definitive site for storage matters.