I've personally had no problems with them (save for one near heart-attack where I lost multiple keys), but I'd suggest looking at their documentation too [1].
It's also worth noting that you don't need to store any keys in their cloud storage, encrypted or otherwise--but you can for convenience.
It's also worth noting that you don't need to store any keys in their cloud storage, encrypted or otherwise--but you can for convenience.
[1]: https://keybase.io/docs/server_security