I like my vivi, on the whole, more than my DCT, at least with the smok dual coil cartos, which is all I've tried so far. I will try a single coil carto on the "DCT" too see what that's like, since I still use it as a backup -- but I'm satisfied with the vivi, and being able to buy pre-wicked bare coils for a buck each is sweet, and just the ability to rewick and coil yourself, is worth the (minor IMO) shortcomings of the vivi "out of the box" - I improved the flavor some just by cleaning the head. Though it's true that the first head I used without cleaning didn't taste so good at first.
The vivi works better for me at low voltage too. Even on the 2.8 I rarely go above 3.3v, and 3.0 is often perfect. So it doesn't work as well on my 3.7s as on a vv, but should work well on a twist I'd guess.
Don't get me wrong I've enjoyed the heck out of the DCT, but cartos in general are a little too inconsistent, at least that's my experience so far. They start off OK, then get really good, then get GREAT for a while, and then start to slip on flavor until they fail, though I've been able to put 20ml or more through a single carto before it performs unacceptably.
Whereas the vivi simply tastes good, if not perfect, almost every time. Just have to keep the wicks WET, especially when the tank gets low. And filling is a breeze. Though some fiddling, or perhaps luck, seems to be helpful.
On the other hand, while the DCT is a bit more complicated to fill, it does work without much fiddling in general, so that's a point to the DCT.
I found I ended up wasting a bit more juice with the DCT, but that was mostly the first few fills. I got better at filling after a while. The nova can flood, but seems less prone to.
They're both inexpensive, and if I had it to do over again, I'd still get both of them, and I'm sure I'm not done trying out different systems
I want another nova, but I think I'm going to wait for the mini.
