Yes. I consider it one of my worst bugs in the Linux kernel and in big servers you pretty much can't have any programs that call fsync() because it will cripple your performance.
That paragraph caused a whiplash of emotions while reading, "Cool!!!... what???? Ug."
Yes, however when you're running a DBMS in your server, I guess it will be doing fsync() all the time. I wonder, if other filesystems like XFS or ZFS have a different behavior here, how much performance gain for a typical database load they can achieve in comparison to ext4.
That paragraph caused a whiplash of emotions while reading, "Cool!!!... what???? Ug."