Did it. Added 44lbs to my deads. I also hardly did all the accessory work. I even failed some reps in the middle weeks
A guy I train with used it to take his deads from the mid 600s to the mid 700s with a few cycles of it.
It's brutal. Don't look for more than a 10% gain each time. I would shoot more for a 5% gain when calculating numbers. Remember, 5% of 500 is still 25lbs. 25lbs gain on your deadlifr in less than 3 months is amazing.