Following up in this. I frankensteined my stash of 6 mg into 12 by getting my hands on some 18 and letting the different mg level juices marry in large LDPE bottles for a few weeks. The 12 is doing it for me. Still have some various mongrels is 6 mg and I notice a big difference. If and when I decide to drop the Nic back I will try and step down to 9. 12 to 6 was just too big a jump. YMMV.