http://preta3d.com/forums/

My experience with Reality - is it's as buggy as hell and a real pain to work with. Its also very slow to render unless you have a very powerful up to date Graphics card. The length of time it took to set up mats etc for Reality and the slowness of renders outweighed the ability to alter lighting while rendering. Iray CPU rendering was faster for me than Reality was and altering surfaces for Iray was much quicker than altering mats for Reality.