The best experience I have had is Media Center playing to
Airfoil, which then handles routing that audio to multiple AirPlay devices.
However this only allows for one source to be played to all rooms, you cannot send different audio to different rooms with this setup.
Media Center would need native AirPlay support to do that, and JRiver have said that they are not going to add it.
You do have individual volume control for each device, and can switch rooms on/off though.
Playback is perfectly in sync, the hardware is relatively inexpensive, and has proven to be reliable. I have AirPlay (previously "AirTunes") hardware which is more than 10 years old and still works well - though AirPlay is limited to 16/44 streaming. (CD quality)
The other option would be a multichannel sound device (e.g. 7.1) playing to multiple rooms at once. (7.1 = 8 channels = 4 stereo zones)
Since it's all playing off the same device, there should be no sync issues.
EDIT: To clarify this, if you are trying to play different audio to different DLNA devices, it may work for you.