SSD's are also a bit of an achilles heel for AWS -- they have their own Nitro firmware for wear levelling and key rotations, due to the hazards of multitenant.

SSD's are also a bit of an achilles heel for AWS -- they have their own Nitro firmware for wear levelling and key rotations, due to the hazards of multitenant. It's possible for one EC2 tenant to use up all the write cycles and then pass it to another, and encryption with key rotation is required to keep data from leaking across tenant changes. It's also slower. We had one outage where key rotation had been enabled on reboot, so data partitions were lost after what should have been a routine crash. Overall, for data warehousing, our failure rate on on-prem (DC-hosted) hardware was lower IME.