Phart I have some B&W photos that are previously uploaded colour photos changed to B&W. It's also good for photos that I take and like but the quality isn't there in a colour photo and I like the subject matter. I think there is an "artsy" look to them.
CC54 I think that some of your top viewed photos would look amazing in B&W.
Give it a try.
I think that they are nice sprinkled within your gallery but certainly not someone's entire gallery.