In this paper we compare various normal form representations of Boolean functions. We extend the study of [4], pertaining to the comparison of the asymptotic efficiency of representations that are produced by normal form systems (NFSs) that are factorizations of the clone Ω of all Boolean functions. We identify some properties, such as associativity, linearity, quasi-linearity and symmetry , that allow the efficiency of the corresponding NFSs to be compared in terms of the non-trivial connectives used. We illustrate these results by comparing well-known NFSs such as the DNF, CNF, Zhegalkin (Reed-Muller) polynomial (PNF) and Median (MNF) representations, thereby confirming the results of [4]. In particular, we show that the MNF is of equivalent complexity to, e.g., the Sheffer Normal Form (SNF), UNF and WNF (associated with 1 and 0-separating functions respectively) and thus that the latter are polynomially as efficient as any other NFS, and are strictly more efficient than the DNF, CNF, and Zhegalkin polynomial representations.