Sometimes it seems tough choosing when to go with B&W and when to go with color. How I would choose is based on subject. Some photos just look better in B&W and others in color, while with some they are on par. Sometimes for me B&W will show more detail than color but for some scenes the colors are so beautiful if feels like B&W takes away from the shot. Keep in mind also that good processing software could also tip the scale either way. I will recommend Mono Art (the default onboard editor on BB10 does a nice job as well), this software adds the filter without decreasing the size of the photo and has some nice filters you can experiment with. Take a look at the examples below and you will understand what I mean.
Photos captured were captured and processed with a BlackBerry Passport.