I actually bought a Fin menthol kit from Wal-Mart while I was waiting on my kGo kit to get here. I thought the menthol juice had a very very nice flavor. Now my wife uses the Fin at night when she doesn't want to use her kGo. I've been cleaning and refilling the Fin cartos for her. The batteries have been holding up for 3 months now, though they aren't used heavily.