The difference in weight is due to the length. If both these arrows were 29" they would weigh the same. I would not expect them to exhibit an equal amount of paradox, but only you can determine which is better. The 2016 is a good choice for the poundage range you mention but a whole inch of length is alot. If the 29" exhibits the best tune, I would expect the 28" to be stiff. You are correct in that you would have to add point weight to counteract the stiff spine. 145-175gr. or more might do it. If the 28" shaft with 125 gr. heads is ideally spined, I would expect you would have to reduce point weight on the 29" shaft to duplicate it, maybe 75-100 gr.