I feel like, as far as cryonics go, it only makes sense if you're terminally ill and are going to die anyway... the process is probably going to be irreversable, but if you do wake up, it means some highly advanced civilization is bothering to revive people from the distant past to heal them, so it's probably a good future?

I'd say it's a form of gambling, though, just because the odds are so poor. (Like, freezing brain tissue destroys it; most cryonics people I see seem to hope that some future supercomputer could use the frozen pattern data to revive their consciousness in a simulation)