Hopefully we'll be adding better Z order controls for both the editor and runtime in future.
C-7 - families work great AFAIK and don't have any issues with for-each. You might want to make a post to the bugs forum if you think there is a problem.
Ashley Do they allow more than one object type? They work fine if you build your entire level out of one object type. I never said there was a bug, just that it is severely limiting. I can only z-order based on y by either hackishly using an array (which it seems I may have to resort to), or using Rex's plugin that does it by layer. But with the plugin, I can't exclude anything.
If I'm using a spriter object, for instance, it will shuffle the objects in with everything else as opposed to keeping them relative to the scml object. So I can't use a family and include the objects I want because I use both tiled backgrounds AND sprites (and scml, but that's beside the point). And I can't simply use the plugin because the spriter body parts are z-ordered with everything else.
It could at least be gotten around with "move forward"/"move backward", but there is no really usable solution to this, to my knowledge, unless I essentially load all y values into an array every tick or so, sort it, and z-order based on that.