I have a truly large head, so it's not really a problem for me. When I was reading reviews, there were plenty of warnings about improper sealing if you didn't have a large / certain shape head.

There's a decent noise floor in my office, and most of the other people use headphones. Even for the ones that don't, there's enough that my music isn't really audible. I'm also pretty vigilant about keeping my volume low, mostly for my own health.