I am new but have been told and read bees will always draw the foundationless frames faster than any type of foundation frames.
They like to draw what they need and don't like to be made to draw what they don't.
In a sheet of foundation the cells are all the same size, be it 4.9, 5.0 or 5.4. When the bees are left to their own accord, their natural comb has varying cells of many different sizes. Large cells for drone, smaller cells for workers and deeper cells for honey.
As for the speed.... What Steel Tiger said.