I was just listening to me MS-Pro's at work, I would actually say that the Bushmills probably leak about 80% of these.
Or maybe I was listening louder? haha. Nah in seriousness, the volume of the leakage overall is probably about 95%, but it is muffled and not as clear.
I just walked about 10 meters from my desk and I could sing along to the words if I wanted to.
I dunno, depending where you work it might be worth buying them to try if you can find some.
That is of course if you have the money to waste on a "test". In saying that, they shouldnt depreciate.
Best of luck with your decision.