We report on pulsed field magnetization and ESR measurements of the family of copper(II)-substituted polyoxotungstates [Cu3(H2O) 3(α-XW9O33)2]12-. (X As, Sb) where the three Cu2+(S 1/2) ions form an antiferromagnetically-coupled triangle. The distinct features are the observation of half step magnetization and hysteresis loops as well as asymmetric/symmetric magnetization between a positive and negative field, depending on the diamagnetic heteroatom X. This is attributed to the interplay between an adiabatic magnetization and Dzyaloshinskii-Moriya interactions. Moreover, the more symmetric magnetization curve of X Sb is discussed in terms of dynamical mixing of a S 1/2 state via a phonon mode.