I've had my Cortex a week or so now. I'm really enjoying it! I've found the Ni200 coils set to about 230C is the sweet spot for the majority of my juices. Big flavour from the included iSub S tank and nice clouds. The MOD itself has an unusual chalkboard texture thats quite jarring at first but I quickly got used to it. The screen being on the bottom is an odd choice and not one I particularly agree with. It can be a bit awkward to change settings etc. Especially when I'm used to the Cool Fire 4 Plus. Battery life is good and lasts around 2 days for me. Overall a nice vape to have in my collection.