The specified lifespan seems to be pesemistic...
Techreport also had a great article series where they tested some ~250GB SSDs to the death. They were all rated in the 80TB range for longevity and while, from memory, none actually failed to read only mode even though they should have, the first died at ~700TB and the last at 2+PB. Yes, that's 2 PETABYTES!
They do state that it was not a statistically significant sample size, but regardless, the worst lasted for almost 10 times the manufacturers stated lifespan.