I've personally had drive failures, fs corruptions due to power loss (which is supposed not to happen on a cow filesystem), fs and file corruption due to ram bitflips, etc. All the times btrfs handled the situation perfectly, with the caveat that I needed the help from the btrfs developers. And they were very helpful!
So yeah, btrfs has a bad rep, but it is not as bad as the common feeling makes it look like.
(note that I still run btrfs raid 1, as I did not find real return of experience regarding raid 5 or 6)