We understand this issue but with cheap motions control and physical interactions will be very limited. Also the gait control will be maybe more difficult.
That being said, there are indeed several applications people can explore without high-end motors. Especially when you are not interested by mechanics or control but rather by software or design. Fortunately, the way we designed the robot (modular and easy hackable) makes this kind of modification rather simple. It will of course require some work to adapt the frame but it should be achievable within two weeks of work.
If we create a Poppy compatible with AX-12/AX-18 motors, we will certainly have to reduce its size to about 50cm. A problem will be the head, for the moment the electronics we have is not ready to be embedded in a smaller robot. We have a plan to do that but it won’t be as fast as changing the actuation of Poppy. So for some times the electronic will be quite non-optimized and you will have to plug all your components using usb cables (camera, motors, sensors…).