I've pretty much come to the conclusion that it's pointless to spend $1k+ on a RAID card if you're only doing RAID-1 or RAID-0... or a single drive. The only benefits are if you are running 3+ drives.

In HD tune my two 74gb raptors have a average of 133mb/s on my "crappy" NF4 Striker Extreme and a minimum of 88.9mb/s and a maximum of 173.0mb/s.

That being the case, spending $1k+ on a card that barely gives me any increase in these numbers is just flat out pointless.