A variety of electrical measurements on the Si/Si1-xGex/Si heterostructure are surveyed. From these measurements it has been possible to deduce effective masses and their dependence on carrier sheet density, the density of heterointerface charge and the interface roughness parameters, and the deformation potential for acoustic phonon scattering. Same of this information is used in a discussion of the room temperature performance of a metal-oxide semiconductor gated enhancement mode device.