Sure, it's a new filesystem; it's bound to have bugs. However, one pain point I've identified is that the existing tools often have no idea of how to deal with APFS. I'm currently typing this from a Mac with an APFS drive that is almost certainly experiencing filesystem corruption–I have folders that suddenly lose track of their contents and become impossible to delete; however, existing tools such as fsck, diskutil, etc. can't do anything to fix the issue, because their idea of how APFS works is woefully inadequate.