Had used Pampers, Nepia, Unicharm (Winnie the Pooh), Merries.
The best is Merries, then Nepia, then Unicharm, lastly Pampers.
The differences between the first 3 Japanese brands are not that significant, but they are way ahead of Pampers.
My bb is not that fussy about wewe in the diapers, even if he is wet with the first 3 brands, he don't cry much. It is with Pampers that he just cannot bear a little moisture.
I thought it is about the water absorbing abilities and the breathability of the diapers in concern.