Clouds and flavor from TFV4 is beautiful. But that things drinks man. Literally suck juice like madness. And it must be wicked in a correct manner, if not the leakage will be a ...... The downside is not being able to change the coils if your tank are filled lose my vote. And the O-rings man... They are there to be broken i guess. I switched O-Rings from the OCC to my RBA, and it still snapped. I used to own one, and now it's just paperweight. Consider the Uwell Crown if you're looking for easy build and good flavor. But still, go for the Serpent Mini.