Total Failure - RAID 5 No Good - DO NOT BUY

Had TS Pro with Raid 5 configured - which was advertised to protect my data in case of a single drive failure. After 15mos running, drive #2 fails - a WD 500gb drive. I followed instructions for drive replacement to the letter, and after it rebooted and "rearranged" the array, all of my folders and files disappeared. Tech support was no help - they admitted their RAID design for this model was faulty and offered only to replace my entire unit. This people should be sued for false advertising. When we set it up, it was also a nightmare and did not want to work on our LAN - had to bring in an IT consultant and paid dearly for installation. I also pay dearly to try to recover my data. This is a cheap NAS alternative - pass it by!!!