I voted "essential", though as usual I see it as part of a larger overhaul to the horizontal, polygonal elements altogether. I would like to be able to select the element type such as floor, roof, ceiling, paving, etc. and then select the form such as flat, sloping, curved, contoured, profiled, etc.
This would allow such "esoteric" things to be properly modeled and identified such as flat roofs that pitch to multiple rain leaders, domed roofs that aren't made of dozens of little roofs or profiled "walls", ceilings that are identified as such (not as floors and roofs etc) and hardscape that isn't a hodgepodge of odd bits.
