Weak and strong form of Discontinuous Galerkin method
 

Hi to everyone,
I have a question on Discontinuous Galerkin methods for compressible flows. In the book "Nodal Discontinuous Galerkin" by Hesthaven and Warburton they say that weak and strong formulation of discontinuous Galerkin method are mathematically equivalent but computationally different. From the numerical point of view which formulation is easier to solve and why?
Thanks.