I'm familiar with all these engines, and have even used a few of them a little. They are very well engineered and will certainly produce games ready for prime time. I am not trying to beat these guys, simply to offer an alternative which is MUCH easier to use and when you want to sell what you made, you can, no strings. Every time I ask someone to send me a very small demo of something made in any of these tools so I can do a like for like visual and performance test, I never seem to be a response. I can only assume the process of creating such a demo is fraught with complications
PC SPECS: Windows 7 Ultimate 64-bit, Intel Core i7 920 (PASSMARK:5008), NVIDIA Geforce 9600 GT GPU (PASSMARK:752) , 6GB RAM