[newbie question] - Has the mirror modifier been changed in 2.78?

Support Basics & Interface
1

Hi! I have been using Blender for a little while now and feel that I at least know my way around the basics and paradigms of the program, but one thing that is currently stumping me, is the mirror modifier, or more specifically how it works in recent releases. Before, using the modifier to model in symmetry was a breeze - loop-cut down the middle of desired mesh > delete faces on one side > tab back to object mode > add mirror modifier > tab back to edit mode.

But now in 2.78a, this behaviour appears to have changed. Rather than before where the mesh would have one editable half and one mirrored half, instead the modifier generates one symmetrised mesh that can be freely edited on both sides individually. This is in and of itself handy, but of course, it obfuscates another feature which I found vastly more useful.

I thought it may have just been me forgetting a step, but I checked through my old video tutorials and found that wasn’t the case. Has anybody else encountered this? Is there something I am missing? Am I just a complete idiot? If anybody has any advice or hints, this newb would hugely appreciate it.

2

I don’t see any change to the mirror modifier

Rather than before where the mesh would have one editable half and one mirrored half, instead the modifier generates one symmetrised mesh that can be freely edited on both sides individually. This is in and of itself handy, but of course, it obfuscates another feature which I found vastly more useful.
Are you using the ‘Adjust edit cage to modifier result’ button (which has always been there) so you can edit either half ?

Supply an example of what you see now and what you previously saw

3

Ugh, yes. I feel like a complete dolt now. Upgrading had apparently unset that option. Thanks!