The Adaptec series is very similar to the LSI card on page 10; look at the performance graphs for yourself. In essence, the 8506 is solidly in the middle of the low-end pack, with the Adaptec trailing. If it's just between these 2, the 8506, but if you've got the money, the Areca cards will blow anything out of the water.
curious why the new XFX SATA raid cards werent included... uses the NetCell storage processor..
True it isnt Raid 5 but rather Raid 3 but I have on running 5 74gb Raptors and I'm way happier with the performance and redudancy over my LSI and Adaptec card I had previous.
I've already lost one Raptor last month and wouldnt have noticed the loss if not for the software telling me my RAID had degraded.. swaped out the HD and its rebuild was fast and completely painless.
I played WoW while it rebuilt the array.. I highly recommend the card.