I have the original Pentax Q and have tried the ones you mention. I got the camera when everyone blieved the whole system would die and cameras went down to ridiculous prices. I expected I would never use except as a toy, a novelty, a conversation starter but I ended using it more then I believed. As others have pointed out the image quality is nothing special (the original Q have an even smaller sensor, it is claimed that the Q7 is better but I really see little difference) but for me the strong point is that all commands are just like in a large camera. You can access everything you need with one touch. Also the camera is very rugged and with the 01 lens attached and a filter there is nothing exposed moving, I have used the camera with a home made protection consisting of transparent film as used in the kitchen under heavy tropical rain with no adverse effect. Finally, if you need things like a 500mm macro or a 1200mm stabilized equivalent this is the cheapest option (maybe even the unique below 20,000 US$). You can find plenty of pictures of the moon taken with cheap lenses and a Q which are not far away qualitywise from what you see taken with telescopes, if you are not into this kind of photography but you are curious to try this on a budged this alone can be a good reason to buy it.
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