Well already said lot of times
WED, GED, MED : All in one should be !

Unity 3D editor, is professionnal like Far Cry one.
-Want a terrain, just create it in the editor.
-Want to choose a model, texture, just download (.fbx) it from the editor

And the team is not the same Size : sure
Team

But A7 remains very easy, and direct for new indies, or programmers. you could use both.

Like Fran_G said it :
The engine depends on your goals, taste,fun , projects etc ...
Lot of people like the simple programming and fast creation on 3GS (i like it a lot also).
With Unity : You must learn interface, tools , physic panel attributes, how code works.
With 3DGS : less features, that what's make it lot more fast to use, and the documentation (magazine ,tutorials etc ...)
is UNMATCHED : SURE !!