You can see from this clip how much I liked doing these.
Another clip from the discontinued WSBB Training Tapes. I was asked to demonstrate, so that's what I did - two reps.
When we did do these, they were used as an accessory exercise or to be done on extra training days. While we all used different reps and sets based on feel, most fell within 4-6 sets using 8-15 reps with dumbbells in hand.
My quads were never my weak point so this was a movement I rarely used. Coming into Westside, my quads were doing too much of my squat and my hamstrings and back were too weak.
My squat was also stuck for three years. Many things had to change to fix this including; dumping the close stance, sitting back, and swapping out my boots for wrestling shoes. It took a year of adjusting and building my hamstrings up but once this was all said and done it put over 75 pounds on my squat (with no equipment or body weight changes).