And another opinion from Switzerland, better late than never :D Purely visually, glossy white or black would be a bit more elegant in my opinion, even if the matte stands the 1723 Tower and Center very well.
But I have decided even in the living room for the matte finish, because as already often mentioned the reflections of the TV or beamer could disturb. If it were only about the music, glossy polished would be my first choice.
However the customer decides, these parts are the madness!!! :-)