I thought I heard somewhere that Seagates may have problems in raid configs, not 100% sure though. How would you run the 4 drives? In raid0 or 0+1? running 4 drives in a raid array would be better with the TX4 cause it has 4 separate channels, the TX2 only has 2 so 2 drives on each channel, not that big of a deal but something to think about.