I've been using single coil cartos in cartotanks for almost a year and a half. I was never a fan of the early clearomizers - they often leaked, had less flavor production, were fussy and inconsistant. I found just the opposite was true with my cartotanks - never leaked, had more flavor, were not fussy or inconsistant.
My daughter just began vaping, and I didn't think she'd catch on to using a cartotank starting right out vaping. I tried a variety of the newer clearomizers available today - Kanger Evod and Protank, Innokin iClear 16 & 30 and the Vision Vivi Nova. We settled on the Protank and the iClear 30 because of their 510 connection.
Today's clearomizers have come a long way from when I first tried them 16 months ago. Still not as consistant or with as much flavor production as a cartotank, but nice. You can't beat their easy fill & go for out & about use. I'm vaping on an iClear 30 on a Mini Provari as I type.