I use a Cherry MX Blue in a cubicle. When I compared it to bottoming out on the rubber dome, the noise level was about the same. But the Cherry MX Blue did have a higher pitched noise, which could annoy some people. I think it depends on the sensitivity of the co-worker. A workplace is inherently noisy, and as long as anybody isn't singing opera, I don't have much trouble blocking it all out.
Nobody had said anything yet, but our office has other concerns, like people talking on the phone, people with annoying voices, idiot co-workers. The sound of the keyboard is the least of our worries.
I used the blue o-rings from WASD for a couple days on my Cherry MX Blue keyboard to reduce key travel, but it didn't do anything to reduce the noise from the click. Also the blue o-rings have a softer landing, so the key return was a little slower when it bottomed out and I actually made more errors with my typing. Maybe a harder set of o-rings will not have the same issue.
Again these all are personal experiences, and I've found that you can only really know with keyboards until you buy the thing and use it. These mechanical keyboards has such good resale value, so it's always easy to recoup much of the cost if you want to get rid of the thing.
