One thing to remember is while all carbon prints exhibit some relief, the effect can vary quite a bit. Machine made pigment tissue like the type Bostick & Sullivan sells (and manufactures) shows very little relief. They do make a version that exhibits higher relief, but it's not as blatant an effect like you can get if you make your own tissue in a manner to exaggerate the relief effect. Some practitioners like high relief, others don't. To a small degree, the type of final support also contributes to the apparent relief.
Yes, the glossy/matte look is also something that occurs with carbon.
Believe it or not, I have lots of carbon prints that aren't any good. PM me and I'll send you a piece of one.
John