[moftz]

I have the 250 ohm impedance versions, they work really well for office-like situations and I used them extensively in college for studying, sometimes not even listening to anything.

However they really don't do a thing when on a plane or in a place with a lot of low frequency noise as passive noise cancellation doesn't work well for that. I ended up buying a cheap pair of active noise cancelling bluetooth headphones for traveling (which are pretty terrible at blocking voices/footsteps).