Well, for me, concept art is very important. I tell this for all people that want to enter in 3D world. I´m not a great drawer, but, before my 3D works, I make some roughts that help me to create, and/or to plan how the best way to model. Draw and traditional sculpt, can help you to understand better de shapes and the composition.
Some people think the most important is the tool (software), but I can´t agree.