I have thought about the consequences. Also, I would hope that it didnt reset.
Right now I believe that someone pointed out (a long time ago and might not be valid anymore) that the drop rates, per person, for getting a named item in a raid are ~10/15/20% (n/h/e). Of course it varies up/down on the raid as well. I dont think that having your completions boost that percentage is a bad thing overall. Maybe +1% per completions is too high, but even if it was .25%, after 10 runs thats 2.5% chance higher to get a named piece in your name. That doesnt mean its going to be one you dont already have, nor does it mean its going to be one that everyone wants. From those same numbers above it was shown that the item list is not equal, the best items are less likely to show up anyways.
The stops to the system are that there has to be a cap on the drop %. 10-20 is too low, over 50 is too high. Allowing people to try and help others get items is what this game is about. Giving a boost to someone that has done the raid many many times is not something that is just handed out, it was earned. Also, as I pointed out before this is not going to guarantee that someone is going to get a torc every DQ run even if all 12 are capped out.
Also, this system benefits everyone. Those that have put in the time grinding for an item do have an advantage, but thats the benefit to putting in your time.
I disagree with the full 20 list because it WILL contain every item available and thats too much certainty. I think that each completion should be helping you get closer to your goal and that it should count each following run, not just every twentieth.