I just compiled the results from 18 respondants. Two respondants had the Oly system with integral dust removal. The numbers have been adjusted where appropriate to account for them. Average TTFD: (Time to first dust): 1.6 months. First dust in 1 month or less: 63% of replies. People who test for dust: 83% Of those who test, the bright / small aperture method if used by: all. All were regular lens changers. 95% keep their camera in the bag when unused. 22% clean their bag to reduce dust. Cleaning (some use 2 or 3 mehtods, Oly's excluded from total): 69% use a blower 13% use a brush 56% use swap methods 89% are satisfied that the sensor can be kept reasonably clean (or kept clean with reasonable efforts [slightly ambiguous question ...]). All are satisfied that their sensor has not been scratched to date. Cheers, Alan.