Just coming up to 100,000 flight hours with my 6. No real complaints, but quietly planning retirement to secondary mass storage. Picked up some surprisingly cheap Toshiba 5TB's for evaluation[1].

Did you notice anything in particular leading up to failure? IO errors, reallocated/pending sectors, checksum errors?

1: http://www.toshiba.co.uk/hard-drives/internal-hard-drives/sa...