This looks like a great card for for either a) mirroring or b) RAID 0 (striping) but not anything above RAID 0. The reason is it has only two IDE channels so if you want to use four drives you'll have two that will be slaves. The really nice IDE RAID cards are setup so that only one drive is on each IDE channel. So something like the 3ware Escalade 6400 (~ $200, 6200, which would be equalivant of this card is ~ $100) has 4 IDE channels (so each drive would be a master).
So basically, to sum it up in my mind, this is a great card for most of us but for servers if you want more than mirroring you should get something else. Now I just need to find out if it is supported by Linux...
Can you tell me what chipset is on the card? Thanks!