When your doing bwt DB rows (or around 20-30 lbs below bwt), for a couple of good reps, your approaching the strongman class. For me, it's still one of those exercise that doesn't do much for lat/back improvement. Would select the curl grip (under hand..medium grip) BB row, as a better exercise for me. But having the knuckles forward, and elbows out (with a lighter DB) hits my posterior delts fairly well. .Oh yeah.....one hand on a rack or forearm/elbow on a bar in a PR, never got into the knee on the bench thing. Good Luck.