We did some pretty extensive renovations to our house recently. Normally, one would use a shop vac to clean that mess up. Our shop vac broke, and I ended up using our Miele vacuum to clean up. Between drywall dust and tile grout and wood chips, the poor vacuum looked thoroughly beat up. There was white dust everywhere, the vacuum was all scratched up with white streaks all over the body and head. We took it into Elite Vacuum for servicing, and one day later, my vacuum looked practically brand new. There wasn't any dust left on the vacuum and all the white scuff marks were gone.
Cost to service was not cheap - the cleanup and filter replacement was $124, but I knew what to expect based on the others' reviews. Through the whole process, the team was friendly and had great communication. I wouldn't hesitate to bring my vacuum in again (though I hope it will be a while before I need to :).