ZFS and sync command

[Ben RUBSON]

Hello,

I'm pretty sure it does, but I would like this to be confirmed.
Does ZFS correctly handles the sync() call / the sync command ?
Will it flush its transactions groups to disk when sync is called ?

Goal is to let ZFS sync option to standard but to call sync command 
after some "critical" steps / operations, so that we are then sure 
data is safe.

Thank you for your feedback !

Ben