My largest vise for heavy work is around elbow height to the jaw tops, others 2"-3" higher, and the next stand I build will be another 2"-3" higher yet. If you're doing serious work in a large vise with larger, heavier workpieces using big wrenches, bars, hammers, etc. you want it lower. If you are using your vise and for smaller, lighter assembly type work, your back will thank you if you mount it higher. Your height and realistic intended use should dictate...