There is really no seeable difference in performance with bullets up 150-160 grains. Beyond that bullet weight, the 7MM Rem mag has the advantage. Heavy bullets need to be seated to deep in the WSM and it costs powder space and limits performance of heavy bullets. I would go with the full size version. If you don't mind the limitations posed by the lack of powder space for heavy bullets then go with the WSM. I don't think the 7MM WSM will survive in the market. I would take that into consideration also if it were for me.