Yes, it has saved my behind several times.
My requirements are pretty simple: has to work well on windows + mac, has to be cloud based, have decent bandwidth, unlimited storage, unlimited retention, and has to and require no configuration of my own apart from selecting files and schedules.
I just haven't found anything with the level of polish that CrashPlan has in terms of UI and usability.
To avoid having all eggs in one basket I try to keep at least a mirror of everything too, e.g. on a NAS.
I have been a DataHoarder kind of guy in the past (dabbled with my own backup scripts, etc.) but found that the chance of user error on my part is probably an order of magnitude greater than the risk of losing data any other way - and with user error there is always the risk that you also bork your backups. So I don't want any system that has any kind of complex configuration on my part.
Further, I don't want to separate the storage from the backup, simply because buying unlimited cloud storage is to expensive. I don't need fast random access storage, I need something cheap like glacier, but that quickly becomes comples. So I'm very happy to hide that complexity behind a cloud backup provider that gives unlimited retention and storage.