I am using Leadwerks right now, but in Gamestudio's defence,
Gamestudio has a free version too....

I was curious and downloaded Unity. I must say, it seems really easy,
and I like the shaders that come with it (even the non-reflective water)...

But, all I can keep thinking of is "no realtime reflections, no post-processing,
no Screen Space Ambient Occlusion possibilities, no dynamic shadows"......
so I wouldn't bother with it...

Gamestudio will always be a good choice.