I used to use a Unicomp in the office - WAY to loud. No one complained about it, but it made me self-conscious when I moved out of a closed door lab and into a cubicle. So, I tried to floss mod it, but I ended up damaging it in the process (dumb mistake on my part). So, then I decided to get a CODE with MX Clears to replace it...only that really wasn't all that quiet either - still no one was complaining. On a whim I got a Poker II with blues, and I find that is no louder than the CODE, just a higher pitch. I use the Poker most of the time, and still no complaints. BUT...I still think it is too loud for the cube, so I have a new MX Black board coming in the mail. I'm hoping that will be just a little quieter. If necessary I'll get some O-rings to soften the CLACK of me bottoming out, but I'd rather not have to. I'm not aiming for silence...just a little bit less noisy that what I have going on now.
I'm also considering a Matias in the future, and maybe HHKB...when I can justify that cost. I have a lot of different locations and systems I work on, so for now, each board will have a place to call home. To be honest, my search for the "quiet enough" office keyboard is, at least in part, me trying to justify buying so many different boards.