I have the blue one. I find it great, I used to have the original coolfire IV but it was enormous like carrying a brick around. The tank design on this one has a great 100% non leak design and the coil literally screws in and out. Its very easy to adjust the coil power as well with the LCD display and controls.
I'm sure there's loads of great mods out there but this is the best I've found.
I'd also never use a mod that can't adjust the coil power because all liquids have different consistency, the thin liquids can take a bit more power to get a good vape cloud, the thick liquids need a little less power because at high power it seems to just burn the thicker liquids.