Let's put everything we've explored into some rational perspective. Here is what we know about hard drives from the two cited studies.
MTBF tells you nothing about reliability.
The annualized failure rate (AFR) is higher than what manufacturers claim.
Drives do not have a tendency to fail during the first year of use. Failure rates steadily increase with age.
SMART is not a reliable warning system for impending failure detection.
The failure rates of “enterprise” and “consumer” drives are very much similar.
The failure of one drive in an array increases the likelihood of another drive failure.
Temperature has a minor effect on failure rates.
Thanks to Softlayer's 5000+-drive operation, we know that some of those points also apply to SSDs. As we saw in the published studies, hard drive failure rates are affected by controllers, firmware, and interfaces (SAS versus SATA). If it's true that write endurance doesn't play a role in random drive failures and that vendors use compute-quality NAND in MLC- and SLC-based products, then we'd expect enterprise-class SSDs to be no more reliable than consumer offerings.