RAID cards

[Redd]

Hey guys, long time regular lurker, limit micro regular, first time CTH poster.

A coworker suggested to me an interesting trick that I've never used before: instead of buying a large hard drive, he always buys two smaller ones and a cheapo RAID0 card.

Because of the nonlinearily in prices, for the same cost he gets about the same hard drive space, much better HD access speed since he has twice the heads, and frees up both IDE ports so he gets maximum throughput on his optical drives.

But it seems like if this idea was flawless, then everyone would be doing it. I'm trying to think of a good reason why this idea isn't more popular. Apart from the slightly greater setup complexity (which isn't a big deal), and the slightly decreased reliability because you only need 1 of 2 drives to fail (which shouldn't be a problem unless you're using the hard drives for a fairly long time period), I don't see any disadvantages. Can anyone provide me with any oher downsides to this setup?