I would say that Japanese discs are better quality. From my experience, japanese imports have sounded much better than their domestic counterparts. I did notice the difference on Zooropa, which sounded much lower than other albums. I held off on buying Joshua tree, since i knew they'd be re-releasing it eventually. If the album already sounds "loud" like "atomic Bomb" or Pop, you probably won't hear much difference. It's only on the low sounding albums like Zooropa, Joshua Tree, or even Red Rocks where you would hear the difference. This is for most albums in general, in my opinion.