I am using Joye SR 510 attys on my KGO-VV Mega. I start at 3.6 volts and work my way up to 4.2 volts.
Four of the flavors I tried last night will definitely be ordered again, make that five, as of this morning (pomegranate champagne, sweetgingerbread, ry4, peppermint and spearmint)...