I have now used my V1 for about 2.5 years but still have not seen any dust spots and not cleaned the sensor a single time, not even with a simple rocket blower. I use several lenses and change often, never consider twice to change, not even in the center of a city and actually not even if it is raining. OK, I do try to cover the body with myself to protect from rain, but I am not overly careful or paranoid about finding a proper place to do it, I just do it as quick as possible. I travel a lot and use it a lot but like I said, never had any dust or any other kind of issues related to dirt. Have any of you ever cleaned your V1 or have had any 'spot' issues? How often do you clean it?