I say that if it continues in the free version will succeed against other engines. I hope it remains that way long. Not only for the engine and also more people to use Unity3D and Turner it popular. Too bad not to have certain things that other engines have it. As an example, an editor of "Path" (Waypoint) and Pathfinder. And some improvements Unity3D more performance in the editor that supports older video cards. In my case I use the video card, "ATI Radeon HD 2600 series AGP" whit-512 Memory Size and Memory DDR2-Type. DirectX10. Some bug detected and have already submitted to the team's unity, support. Keep a good job, in my view is an excellent 3D engine.