My DS2072 is not particularly noisy, but it's the noisest thing in my lab and it kind of bugs me. I've seen lots of people talk about replacing the fan to make their scope quieter, but I don't think I've seen anyone report back.
I suspect a good portion of the noise is the wind through the grill, not the fan itself. If so, replacing the fan won't help much.
Who has done it and what were your results?