Just got back from the PH Tokyo and used these there. They took them without a fight and the exchange rate was pretty decent. I got 87 yen to the dollar on them, when the rate offered outside the hotel was ~91 at a good spot and 89 at a poor spot.

When you consider I got these at 20% off face in the first place, it's well worth the poorer conversion rate.

YMMV, but these seem pretty viable for international use as others have said in the previous hundreds of posts.