Remove the jaws and route the edges that you could not route while they were still attached. Then use a roundover bit on all of the corners except the inner edge of the inner jaw of the end vise. Give everything a lite sanding, and apply Danish oil to the inner surfaces of the jaws. (By "inner surfaces", I mean those surfaces that will not be accessible when the vises are assembled - the inner surface of the inner jaw, that bolts to the bench, and the outer surfaces of the outer jaws, that bolt to the vise plates.)
Stop it. Really. I mean it. Pick a height between your thigh and waist that seems right. You’ll adapt. Don’t worry about your back. You’ll adapt. If you are really uncertain, make it a little taller and then cut down the legs. After a decade or so, your work habits will put a magic number in your head. You’ll have built enough furniture that you will know your number. Until then, pick a number.
Beyond the weight capacity, the Grizzly is also the largest table top on our list and in more ways than one. For a workspace, the Grizzly provides 5’ of length by 2 ½’ of width. There is not another table that really comes close to that size. Another size advantage of the Grizzly bench is the table top’s thickness. While the standard thickness of the table top for a quality woodworking bench is 1” with lesser models often offering only ¾” of thickness, the Grizzly provides a 1 ½” thick table top.