I actually like most of the clearomizers and cartomizer that I've used so far:
clearos: iclear16, 30 & 30S, Kanger Protank2 and PT2 mini, & Vivi Nova
cartos: Smoktech dual coil, single coil, Boge and various short, tankless cartos.
I think they all have their good points and bad, its really how you use them in combination with various juices and devices. For example, I can crank up the wattage and get very rich flavor and warm vape with the iclear30 series, but wouldn't do the same with the Protank2. I can run the Protank 2 off a VV ego battery and have a very crisp, cool tasting vape, but that wouldn't work so well with the iclear30-s.
I can change the draw resistance with all the devices using various plinths, drip tips and/or orings; everything is really customizable to your preference.
I like a mix of fruit/mint for my dripper carto's, sweeter fruit flavors in my cartomizers and a more citrus based fruit flavor for my clearomizers.
All produce great vapor (I use 100% VG only) and taste, so favorite for me really depends on my mood for what I feel like having, and where I am. (I use the PV at home, I use the ego style when out)
