The X-Mirror behavior is being discussed, it may change in Blender 2.8.
In Blender 2.79 (current way) it’s a per-object option, meaning each object have this feature enabled or disabled.
The proposal is to change it as a per-mode option, so that it will affect any selected objects. Turning it on or off will change it in a global way.
Some of the pros and cons:
-It may be a hassle to enable it and disable it on selection change. Generally, an object is modelled in a symmetrical or non-symmetrical way, and you don’t want to toggle it each time.
-Having it per-object is an exception, and may seem not coherent compared to other tools
-Other 3d apps generally have this feature per-mode
What do you think about it?
- X-Mirror should be per object
- X-Mirror should be a global mode