Blender Subd Navigator

This utility adds four menu items the to 3D view menu:

"Subdivide Selected" will add subdivsion and decimation modifiers to all the currently selected objects.  if you are in object mode this add a subdivision modifier so you can use edge creasing in edit more, if you do this in sculpt mode, it will add a multires modifier so you can sculpt w hierarchical subdivs.

"SubD More" will set the subdivsion and multires modifiers for all the currently visible objects one level higher.  when it hits the max res, it will activate the decimator.

"SubD Less" will set the subdivsion and multires modifiers for all the currently visible objects one level lower.  if you are at the max resolution with an active decimator, it will deactivate the decimator.

For those who like to switch back and forth between zbrush and blender, I recommend moving the default blender shortcut for duplicate from shift+D to ctrl+D and then binding the following hotkeys:

alt+D = "Subdivide Selected"
D = "SubD More"
shift+D = "SubD Less". 
numpad enter = "Toggle Workmode"

if you are in Sculpt mode and use "SubD More" and there are no SubD modifiers, a Multires modifier will be created for the active object instead.  This is the primary difference between the default ctrl+0-9 hotkeys which only create a subdiv modifier.   Because this uses increment and toggle, it's 3 shortcuts vs default 10. Easier on your knuckles for such a high traffic shortcut...

warning.  Due to Blender limits, if your mesh has a high poly count you may encounter long delays or errors after subdividing.  Also if you have multiple objects visible in the sculpt room, only the active mesh can be sculpted on.  

updates and most recent fixes can be found on github:
https://github.com/spiraloid/Spiraloid-Toolkit-for-Blender/blob/2.90/Addons/SubdNavigator.py