Digital BW, The Print

Thank you, 
and if I may ask you to indulge me, one more question.

Is there any particular advantage to converting images captured in 
RGB (I use a Canon 10D) to greyscale, as opposed to converting in 
layers to mono and adjusting the sliders, or for that matter de-
saturating in layers (PhotoshopCS).

Thank you in advance.
M. Olson