Superb!
+1.
Reminds me of a three week trip to the U.S. Southwest several years ago with my Canon 5D. One early stop was White Sands, during a sand storm. Of course I had to photograph it, it was so stunning. I was smart enough not to change lenses while out in the storm, so I thought I was OK.
But when I got home and started processing, every image with blue skies was filled with dust specks that I had to individually spot in PhotoShop, as well as cleaning the sensor.
Soon after, I upgraded to a 5DII, with the automatically vibrating sensor self-clean feature.
The 5D lens mount wasn't tight enough to keep out flying dust at all.