Just an observation and some thoughts about the V2 and the 801 carts. I find that I get very good performance from my atomizer when I top off, and that lasts for a while. Then the performance starts dropping off a bit, you have to pull longer to get the vapor/TH you want. I suspect that the atomizer is now saturated and just at the point where it is hovering on the over-saturation point. I think this affects how the coil works. I think it may be supplying too much liquid to the coil to allow effective vaporization. What I've started to do is, when it gets to this condition, pull out the cart, install just the whistle tip, and vape for a while, working off the
juice already in the atomizer mesh. I can get at least 20 good drags in this condition, with good vapor and TH. When that starts to taper off, I replace the cartridge and I'm good to go for quite a while longer, usually until the cart is nearly completely empty. I think this also minimizes buildup on the coil. I'm not sure this would work for every atomizer/
juice combination, but it seems to work on mine fairly consistently, and stretches my juice out pretty well.
I'd be curious to see if this works for anyone else.