For blender 2.8 use GroupPro 2.x series.
For blender 2.7x, use GPro 1.1.6.
GroupPro was made because default blender group instances are powerful, but they are not user friendly to work with. With GroupPro I managed to get rid of all annoying features of group instances:
- you can edit any instances on scene, not just the 'source' one
- you can work in recursive way - group instances, can be made of other subgroups, which can be made of subgroups etc. At any stage subgroup can be edited and saved, with all instances updated in real-time
- easy mirroring of selected groups (fixes group instance mirror bug in blender)
- adjusting origin of group, without destroying positions of other instances placed in scene, or in another groups
- ability to edit linked libraries groups directly in current blend file
- ability to crate group proxy
This makes working with huge scenes with lots of objects easy and gives all the pros of group instances:
- less memory memory usage
- easy selection of multiple objects with one click
Here is video tutorial/demo how to use GroupPro (now new videos):
And blenderartist thread with QA:
You will get free updates whenever there are new ones.
Update 2.0.8 and 2.0.9(for Blender 2.8 only)
- fixed initialize function
- flip - now is aware of previously created copy. It will update its position, instead of creating new instance of flip
- Added ability to group collections. See vid: https://www.youtube.com/watch?v=RcreHIRw3f8
Update 2.0.11 (for Blender 2.8 only fix)
- grouping collection now fully supported (Right click in outliner -> 'Group from collection').
- quaternion option added to preferences (prevents gimbal lock that may sometimes happen with euler object rotations, but less user friendly that euler rotations)
- More options for Flip operator (new coordinate systems - global, local cursor)
- Origin to center of bounding box added
Update 2.0.12 (for Blender 2.8 only fix)
- added local mode options: tree, list
- option for linking modifier objects added
- option for linking children objects added
Update 2.0.13 (for Blender 2.8 only fix)
- added 'update addon' option in preferences. When next release of GP will be out, use it to automatically download and install new GP version. Hopefully it will work :). Problems may be reported eg. on discord: https://discordapp.com/invite/cxZDbqH
- improved pick group - gives more predictable results, bugfixes.
Update 2.0.17 (22.05.2019- will work only with blender builds after 21may):
- Compatibility fixes for latest blender release (after 21 may)
- Added option to un-instance meshes when creating Group Copy.
Update 2.1.0 (12.09.2019, for blender 2.8)
- Added Proxies generation support
- added ability to edit linked libraries groups (beta)
- new documentation
Update 2.1.3 (19.11.2019, for blender 2.8)
- fix bad bounding box drawing, when using 'set origin'
- 'create group' will use active object collection as target for placing new group empty
Update 2.1.5 (12.02.2020)
- better handling of broken groups,
- opening group will now make its collection active in outliner
- added - apply transformation (loc, rot or/and scale)
- fix drawing of bbox after refactor
Update 2.1.6 (21.02.2020)
- Pick Open - you can now scroll to change opened hierarchy depth,
- fix isolate view,
- material menu - added 'Change color'
- UI cleanup
Update 2.1.7 (23.02.2020)
- you can now snap to the corners of group bounding boxes (for old groups you have to open them then close - after that corner snapping will work)
- fixed SSL certificate error problem
- added faster material color update
- added option to disable bounding box vertices