Re: An important question : SSD failure modes?
> All the HDDs I had failed completely without warning.
I have only had one HDD fail without warning ever. I've had plenty announce their impending demise through SMART. Based on my own PERSONAL FIRSTHAND EXPERIENCE, depending on diagnostics from the drives themselves has not been a dangerous game at all. It's very useful even with notorious models from bad vendors.
Self diagnostics on drives is highly useful. Poo-pooing drives that fail to provide this is unconvincing.
Ignoring this feature is good enough reason to kick a particular SSD brand to the curb.