Theres a reason its old, cause they never needed to change it, its just so damn good, en entire company built on one headphone^Some reviews says PX100-II is better in sound quality. Plus the Portapro drivers are pretty old. And in India Porta-Pro is costly about 4k with no warranty?, while PX100-II can be bought at 2.8-3k if one knows where to get it with warranty.