I have 2 buffalo terastation NAS drives, a 1TB and a 2TB running in Raid 5. The 1 TB is about 2 or 3 year old and the 2 TB is 12 months. Running 24/7, no problems thus far. I was a little sceptical when getting the first one as some of the reviews were not so good but I'm happy with them, do what I need plus I can FTP into them when I'm not at home to access my files.