Once, Matt from Lifestyle gave me this explanation :
BeoSound
differences:
MK1 – Glass is prone to falling off when mounted vertically, unless already
rectified by Bang & Olufsen!
MK2 –
uprated glass, can be upgraded for use with N.MUSIC (BeoPort/BeoMedia) if
required.
MK3 –
uprated CD mechanism, ready for N.MUSIC use.
when your Black Label begin to taste like juice just take shot or two of Absinthe and
after that quench with some vodka, if you still feel juice like take beer
with grappa !