I've used cartotanks almost exclusively for over a year. They always provided me with more flavor production than clearos, which to me often muted flavors.
About 4 months ago my daughter asked for her own mod setup for her birthday. As a novice, I thought that clearos would be a better fit for her college lifestyle, so we auditioned the following clearomizers. Innokin iClear 30, Kanger Protank 1 & 2, and Vision Vivi Nova. Our concensus favorite was the iClear 30.
The iClear 30 has a higher juice capacity, dual top coils, 16 wicks, an adjustable mouthpiece, and comes in multiple colors (A big plus for my daughter who likes to match tank colors with the colors of her mods.). I've since been using a couple of iClear 30's in rotation with my cartotanks; their flavor production is only a hair less than my cartotanks. I also kept the Protank 1 and although a fine performer, it doesn't compare to the iClear overall.
Daughter's setup: Pink and purple AltSmoke BBs and iClear 30 clearomizers.