Sony keep their internal strategy on such things fairly quiet, and they are also not paricularly good at encouraging the robot hacker/modder community, although they are warming up and improving.
Their platforms are clearly some of the most sophisticated in commercial mass production, and have the largest ranges of sensors and degrees of freedom. However - their robots are also some of the most expensive.
Time to build your own robot! Using a Raspberry Pi with parts and some time, you can use my book to learn how to make and program a robot with automatic behaviours.