A detailed hydrodynamic characterization in the transitional flow regime of two variants of the Norstone Polyblade (R) high-shear impeller (HSI), of industrial relevance, is presented. The study was carried out on a simulated Newtonian fluid using computational fluid dynamics (CFD). Measurements of power number were carried out to validate the simulation results. Hydrodynamic parameters considered of key importance in powder dispersion processes (i.e., viscous dissipation and effective circulation) were used to assess the impellers' performance. Furthermore, their performances were compared with reported data for two ring-style HSIs of two and four rings, and power number measurements of a sawtooth (Cowles-type) impeller.