do you mean mmx300? i dont think they worth the price instead mmx2(based on dt231/dt234) are recommended. But based on user review, it put pc350 to shame link
about pc360, since pc350 having bad sound quality, maybe sennheiser does fix the pc360, it does look like hd558, maybe it does sound similar to hd558, it seems that from user review, they are sattisfy

my bet if you can manage to get mmx300 for cheap, better go for mmx300 else get for pc360 or normal audiophile headphone