I like Gamestudio because you can program a game from scratch without any editor. If your imagination is good enough you can make a game without the need of touching the horrible MED or WED.
In Unity you always have to use the (for my taste, lame) editor with it's stange interface.
I don't like the behaviour approach. I like a clear structure where you always have the complete overview about your project.
I love classes, so I only use the c# wrapper for anny projects.