I recently moved from Lumix to Fuji X-T1 (and no regrets) but sensor cleaning is an issue. In all the years I owned numerous Lumix micro four-thirds cameras I didn't have to clean a sensor once, I've had an X-T1 since Christmas and had to clean the sensor twice. So either it attracts the dirt, or the ultrasonic cleaning isn't as good as the cleaning on the Lumix cameras. I use a Delkin Devices Sensor Scope kit to clean the sensor, and find it easy to use.