Aren't high-grade intersections best? 30 meters @ 14g/ton of gold seems better, to me, than 60 meters at 7g/ton, because of the base price of uncovering, digging, transporting and processing each ton of ore. Other things (like depth) being equal, isn't a high-grade lode much better than a low-grade load containing the same reserve ounces -- or is this thinking flawed?
I've liked to see double-digit grams per ton, though I'm aware that successful open pit mines manage with much less.
FL