I worked at a nuclear facility and also couple of coal fired boilers and welded more xxs tubes, steam drum headers , economizer & water wall tubes and high pressure lines through out these facilities than I care to remember , for 35 yrs (started in '82 @ the power plants ) . and its not even close in quality of the two rod brands. Never did I encounter anyone who would take the cheap atom arc rods over the excalibur, the only people who wanted the cheap atom arc were stingy mgmt superviors who were worried about their budget.
I am guessing you just want to go against the grain here-- thats fine with me