I'm using CrashPlan and I have recovered multiple files over past couple of years, that I either mistakenly deleted or overwritten. I haven't tried any full-scale restore, yet, though.
CrashPlan lost some data of mine in 2013 from querying a corrupted Volume Shadow Copy Services database on Windows. (At least, that was their explanation. I'm surprised that their client did not independently verify the data after it was uploaded.)
I moved off CrashPlan in 2016 because their upload speed continues to be embarrassingly slow outside the US even with deduplication and compression turned off (they have a datacentre where I'm at, but it's for Enterprise customers only).
They also highly recommend having 1GB of RAM for every 1TB backed up, which sounded a bit unreasonable to me.
I moved to Acronis True Image when they offered unlimited cloud backups with their 2016 version. They probably couldn't sustain it, because I had to pay a lot more for backups when I wanted to renew in 2017.
Now, I'm using both Arq and Synology's Hyper Backup with Amazon Cloud Drive. One of the problems I foresee is that while Amazon doesn't care how much data one stores in Cloud Drive, they have suspended users for downloading past an arbitrary limit in a certain period of time — so full restores might not be possible.
I moved off CrashPlan in 2016 because their upload speed continues to be embarrassingly slow outside the US even with deduplication and compression turned off (they have a datacentre where I'm at, but it's for Enterprise customers only).
They also highly recommend having 1GB of RAM for every 1TB backed up, which sounded a bit unreasonable to me.