candle_86 wrote:I can see a few reasons, though ATA100 has the same benefits, it will allow you to break the 127GiB barrier, as 48bit LBA was implemented with ATA100, can provide hard ware raid if your board doesn't, can run IDE Cables along the bottom of the case if you put the card in the lowest PCI slot, helps with airflow and cable management
Cable placement is a good point as this is often something motherboards get completely wrong. The 48bit LBA barrier isn't so much an issue with ATA133 as it is it's own thing. ATA-6 specifies 48 bit LBA with UDMA 100 signaling, so it's more critical to check if a controller is LBA48 compliant. ATA133 won't even guarantee faster hard drive access as different implementations can result in good or poor performance.
"Hardware" RAID isn't really that great a thing unless you're going with 3ware (for IDE) or a SCSI RAID controller. Most SoftRAID controllers from Promise or Highpoint depend entirely upon driver support to implement RAID and create an unreadable format for recovery purposes (unless you have the same controller in the recovery machine). 3ware cards accelerate RAID in hardware, so they're certainly very nice if you can find one.