It looked like a great idea, and don't get me wrong, I use it every day (everyone else in my workplace likes the heating a lot warmer than I do). I even love the box it came in!
The touch switch works well. One touch for low, then a double-touch for off. I don't often run it at full speed.
At low speed, it's still noticeably louder than all the other general background office noise - my computer's fan, the building air conditioning, and so on.
I play very soft music or radio at my computer, and yes, I can still hear it over the fan, but even on low, the fan certainly isn't quiet enough to forget it's running – there's a constant "whoosh/rumble" sound.
On fast? It's not "jet engine" level, but it's (subjectively) more than twice as loud as low, and it's far too intrusive and noisy for me to leave it on fast.
The noise seems to be caused by the air flow, rather than bearing noise, so I think it's a basic air movement/blade design issue.
On the plus side, if you run it on fast for a while, low speed sounds quiet :-)