How much testing did you do? The latest engine reviews often rated Unity3d as the best tool. And I got some feedbacks from our customers as well. Many people just like this engine because of the complete real-time tool-set and the good tutorials plus several scripting options.
Some coders still prefer more flexible solutions like C4 or Ogre. This depends on the needs of a project.

Since I am no Mac user I cannot write about my own experiences. The features are impressive though. We will all get a clearer image if they release windows tools.

But we have to realize: Unity3d got so much customers in such a short time. I also know some Torque projects moving to Unity3d. There must be a reason. Many mac-users are graphic artists and they are lucky with Unity3d. So the editors must be intuitive. Think about new developers - just entering the gamedev field for the first time. They love intuitive tools, real-time feedback and good visuals including modern shaders and shadows.
This is the future, this is what our graphic cards are made for.