I'm one of those who made a stylistic decision not to wear browns, specifically mid-tone and dark browns; I do wear tans, taupes, camels, caramels, and cognac. I made an exception for leather items though, and have a few but not many leather things in mid/dark browns, and am really looking to add more cognac (soooo nice paired with white!). My primary reasoning was simply to keep my urban/punk side strong and keep from looking earthy. I also often feel too "muddy" in the non-light browns; the darker shades tend to wall-of-brown into my hair, but the lighter shades I can mix in in ways that feel crisp or soft.
Very dark brown in particular I tend not to gravitate towards, but I did pick up this faux leather jacket in a so-dark-it's-almost-black at NAS which I am still waffling a bit on (if it were real leather I don't think I'd hesitate as much). I need to spend some time playing in my closet with it, but it's finally nice and warm here so I'm having trouble making myself do it
I don't know that adding brown would necessarily up your style quotient on its own; plenty of stylish ladies wear it, and plenty of stylish ladies don't. If the brown is right for you, and you want to add a bit of softness or earthiness, it's is great at that. Brown is also fun to mix with black to soften an otherwise harder look; mixes with browns can be quite rich looking. I'd say make sure you are comfortable mixing brown with your other neutrals and the colors in your wardrobe. If you aren't, then you do risk orphaning new brown items. If you're not sure, then it's worth picking something up and playing around with.