The material is important as you want the cone to be fairly stiff but also to be internally damped. Stiff and light is good but you don't want the thing to ring like a bell. So a weave or a pulp construction or a light fabric impregnated with viscous damping fluid or two light materials sandwiched between a viscous fluid is critical to avoiding ringing.
B&W are often dismissed by audiophiles but in all honesty although they make more models than Imelda Marcius has shoes, they do use good materials for their midrange cones rather than cheap north european metal or ceramic drivers that ring like a bell (sound awful or need notch filters to sound mediocre)
Which is better for you ? I can't begin to guess - try to get some auditions in.
B&W are often dismissed by audiophiles but in all honesty although they make more models than Imelda Marcius has shoes, they do use good materials for their midrange cones rather than cheap north european metal or ceramic drivers that ring like a bell (sound awful or need notch filters to sound mediocre)
Which is better for you ? I can't begin to guess - try to get some auditions in.