I was looking at the QX1 a while ago as a cheap way to get into Sony lenses. There are even some iPhone cases that dock the sensor directly without the need for that flimsy clip. The setup is rather strange: you have onboard memory and live transfer to the phone. The onboard card is required to shoot video or any type of fast action still photography.
The Sony app on the iPhone isn't any better than the canon live view app for its DSLRs: slow to respond, high latency, clipping in video, slow to change settings.
Now this isn't a problem when using the phone as a remote in a DSLR, but when this is the brains of the camera, you are going to miss a lot of shots and get a bit frustrated. Remote apps work ok for some things: macro, staged shots, etc. but not for shooting fast action.
The QX seemed to be an evolutionary dead end. The has not been an update on three years.