I think these dual coils haven't changed at all...I think we have built a tolerance to the bigger vapor production..When I first got them It was WOW!!! HOLY S**T!!!! Now its just nice... I vape at 4.2(3.7) , 6, and 7 volts... I use many different cartos. Singles, duals at 1.5, 2.0, 2.5, 3.0ohms... Yes I do get a bad carto once in awhile, sometimes too much, but If I use a carto that cost me 3.00..I still saved 3-5 bucks a day on those coffin nails...So I don't whine and complain, that these cartos suck or got worse..vaping is saving my life...