It always seemed to me that varying the rate depending on the country was about the simplest and fairest part of the old system. It's all vey well hankering after a flat rate, but bear in mind that in the UK you get about £17 for each 24hrs and the $50 that was suggested some months ago is worth naff all now. It won't seem like such a good idea when you find yourself somewhere that your flat rate won't cover your lunch.
This will have to be sold as a cost reduction measure, so I wouldn't expect "some you win some you loose", more like "you loose." That said , I conceed that it will be better than what we have now.
PS, BZN are still on JPA actuals.