I have been doing deadlifts in the rack starting from the top for about six months now and have found my deadlift from the floor has made dramatic increases since then. Basically, I set the hooks to hold the bar at the level I would use if doing rack pulls. I always use straps when doing deadlifts from the top. Strap up, lift the bar and take a couple steps backward, tighten up your core then slowly lower down to the floor, allow the stretch reflex to assist you in pulling the weight back up. This can effectively work as a sort of negative version of deads because you can use loads greater than your 1 RM off the floor and still complete a full rep. As a side effect, I've found greater growth in my erectors and traps than I have experienced in quite a while. I recommend everyone who likes to deadlift to try this out. I alternate between these, standard deadlifts from the floor and throw in some rack pull training in there too. As a result, I'm getting close to hitting a 600 lb deadlift quite soon. A few months back, I pulled 545 from the floor. Just recently, using top down deads, I was able to do 545 for three full reps, which I doubt I could do from the floor at this point in time. I plan to attempt a 600 lb deadlift from the top very soon and if I get it, I know that 600 from the floor will be right around the corner. Anyone else willing to try these out? I can record and post a video this weekend if my description is not clear enough.