Now, I love my M401. It's great, but not a "use at work all day" kind of great. I am really thinking hard about getting the Janty V2. I have only one question which needs answering: How long do the carts last? I know they are larger than the M401 and probably last longer, but by how much?
The Kissbox/801 carts last a good while, if you can build a good one. I had the best luck with polyfill + straw mod. I measured around 36 drops will fit in a completely empty cart (no filler). That's a hell of a lot of juice.
I noticed that if the stick is used with carts, and the stick is faced downward in your pocket, the liquid will wick really well into the atomizer. I was never able to get the carts bone dry, not even close, BUT, with the Kissbox/801 carts, you won't have to top off nearly as often.
I have to say though, I've become a dripper as of late. It's just less of a hassle for me and it seems to provide a better flavor.
It also comes with a handy leather pouch which you can hook onto your belt. Very convenient for using on the go.