in unity 3D You already have great floor textures and free additionnal bunch of real quality floor textures ! You have really good quality trees and animated grass to start your game. Something Torque 3D is following by putting quality 3D assets and characters now , they have understood !
Unity 3D is more artist side : you sculpt , paint terrain , paint vegetation , all that in real time without quitting the editor
I also use Unity Free for a Free roaming RPG action , caus i can edit any time and directly the terrain, vegetation and texture, i can import my models and textures for 3D assets and you can see them in the editor as thumbnails ... etc ... etc ... I don't have to care about terrain shaders or even terrain coding or tools, i just have to create !
I just wanted to spot, that with A8 only few people make good terrains, not a lot are seen in showcase ...in Unity you can find good terrains made by beginners everywhere !
We won't go in another flamewar A8/Unity, this thread type already exists and lot of people will say paint them in photoshop or use another third party tool I know , i know ... When Shiva 3D, Torque 3D, C4 engine,Unity 3D, Esenthel engine etc ... have their editor, A8 is just behind and no one here cares about a real complete terrain editor integrated in A8. So i stopped talking about that, and i talked now, but i stop caus i know nobody cares about that
@Superku : Sorry but your question as started my long response