Ive been fine with 18mg juice in mine. I can get a throat hit with 12 in my ego, but not that satisfying. The only thing i note is i have to switch in the evening when my throat builds a tolerance to a stronger batt. Im using my ego much less now, as i used to start the day with a kr808 and switch to ego, now im starting with eroll and switching to kr808.
I also have some thicker liquids, they seem to hit fine but have trouble soaking into the atty, so if i take a bunch of hits too quick, i end up with some burnt flavor. The thicker the juice the more time between drags i guess. Im using 80/20 ecblends in it and they work really well, despite the high PG content not throwing a lot of cloud. The TH is satisfying and i can hit it a lot more without getting burnt taste