Sensor dust is the worst. I switched from shooting on Canon DSLRs several years ago and now shoot on Sony mirrorless - the NEX-7 and a7R. Because I exclusively use primes I tend to swap lenses quite a bit and as a result my sensor gets dusty fairly quickly without a mirror to shelter it. Even with a blower bulb it tends to show up. This isn't much of an issue because I also like shooting wide open including down to f/0.95 and sensor dust is never an issue when shooting fast, but then I'll decide I need to go to f/11 or slower for a landscape shot and boom, I've got smudges in the photo thanks to the dust on the sensor.
Yep, I'm on a Fuji x-pro1 mirrorless. Ended up getting a boulder of dust on my sensor when switching lenses at the top of Castillo San Cristóbal in San Juan.
If only this was true for dust on the rear element of the lens as well.