It's my first post on the forums..
I'm new to Rhino but I've been using 3D professionally for a good while (3DS Max, Maya, ZBrush, Softimage, etc.). I was genuinely surprised to find a lack of scene management feature(s) like Maya's Outliner missing; it's such a basic feature for modeling software. I thought I must be doing something wrong because I couldn't find it until I read a post on the forums confirming it doesn't exist. (Please correct me if I'm wrong about this!)
Please consider adding this feature for Rhino 6 or as an update (IMO this really should be part of the application and not a third party plugin). Being able to select, filter, rename, organize (by name, type, etc), group, hide/ unhide/ render type, set properties, basic organization, etc. is a must have for productivity and workflow optimization.
My favorite flavor of scene management tools in other software is Maya's Outliner but there are some other good implementations as well:
The Explorer (XSI)
Scene Explorer (3DS Max)
Select by Name (3DS Max)
Schematic View (3DS Max)
Model Tree (Inventor)
Having said all that I'm really enjoying using Rhino and I've been having a lot of fun with it. It's been a long time but using NURBS again full time is like slipping into a warm bath.