Has anybody had any experience upgrading the drives in a Pegasus Promise RAID? My current setup is the 6x2TB model, but I'm running low on space. I'm considering buying 4TB drives to replace each of the 2TB drives. 1) The cheapest drives are Seagate 4TB external drives. But conceivably I could just take these drives out of their enclosures? 2) The other alternative is 4TB Hitachi disks but they're considerably pricier. Any thoughts, feedback or advice? Thanks in advance!