I voted both, I dont believe one is better than the other. I have been fried from the flat iron and it took lots of work to get it back into shape. My freshmen year of college my savior was tthe flat iron. I washed weekly, oiled with WGHO, flat iron and roller wrapped my hair and by the end of that year my hair was very thin, see thru ends and all. So I just fixed it by cutting it off andd starting over right...... Sorry to go on and on, but they both are hair killer. Since I only use heat on my relaxer day which was every 6 months finna be every 4 its not that bad for me cause its only that one day.