16bpp has always been the Maemo standard. AFAIK LCDs cannot display 24bpp anyway, but more like 18bpp. I don't know whether this is true for AMOLED, though.

On my N9 I can see very weak lines on bright white areas, but only if I look closely. Apart from that the display is fine.
Of course it has this green pentile tint when watching it from angles where on regular LCDs colors would totally get washed out.

IMHO if you're using the device normally, the display looks gorgeous. But if you look close, it becomes ugly.