Had both those heads in my quiver a couple years back. Only grims in there now. While very accurate, the ulmers are not near as tough as grims. And as much as i hate to admit it, i lost a wt doe with the edge too. Could have sworn it was a perfect broadside shot at 17 yards, just as the sun was setting. Full penetration with the arrow, she turned and ducked back into the thick stuff. Not so much as a drop of blood to be found. Went back and grid walked in the morning, couple coyotes and magpies was all i found. That turned me off for good.
Have nothing but good to say about grims, with a dozen kills with them on mostly mule deer, a few whitetail, and antelope, bear, and elk. They put down animals very quickly.