This article is devoted to an examination of the application of one- and two-equation porous media theory for modeling the thermal-fluid behavior of stacked multilayer micro- or minichannel heat sinks. The objectives of the article are to examine generalizations of the geometric scaling that is elucidated by adopting a porous media approach. This article examines the relative accuracy and computational efficiency of one- and two-equation approaches. The error between the two models and the experimental data is examined by an error map given as a function of conductivity ratios, Darcy number, and Reynolds number.