It certainly is if it's only in the first few weeks. Anything less than a year.. (assuming a normal environment of course) A mill floor is something different!
And something that's not possible for most people. The Studio wasn't built to be easily accessible to clean.
The teardowns didn't show that level of detail for the fans, but I'm willing to bet not. I'm almost positive it's a harmonics problem with the fans, and probably an execution flaw. I think they designed the fan system that any little manufacturing difference throws all the harmonics out of whack. For me there's a sound right on the edge of my awareness that just plain bothers me when I'm sitting at my computer desk. If I were working from home all the time I'd have had to sent it back, but since I don't, I can live with it. It's not like I don't have other machines to use if gets too annoying. I still like the machine too much to get rid of it.