Real good stuff - I do it w/ 95lbs and do sets of 6 - usually 5-6 sets is all I can stand.
Great part is there is no muscle fatigue - actually provides a great stretch for me. Running or HIIT seems ot have a negative impact on my squats so I avoid them at all costs.
I ran a buddy through it at lunch today - he is a fighter and ran 4 miles prior to doing it - he was wasted after 5 sets of 6 w/ 95lbs. Granted he had never front squatted before so he was holding the weight w/ his shoulder the whole time but still.
I would guess at 17 your form on these lifts is a key factor and doing something like The Bear is good b/c you can get in good rep work w/ minimal weight.