All coils seem to be good sold with the new tanks. While the tanks are good sellers the company takes care of making coils until the time comes that they can not keep up or new tanks come out and they redo their machines for the new tanks. I believe then they sub out the coils and quality goes down hill because the original company wants to make the same money and the new company wants to make money and the only way is to cut corners and cheapen them down to do it. Seems to happen with all companies with coils. This is my opinion only and others may differ with their opinion. CHEERS!