The mini Vivi is a different design. The top is a cone which allows liquid to go back into the tank via the atomizer. The large Vivi is actually flat and has a ridge in it which traps the liquid. the mini is much, much better!
The stardusts...don't get me started. So inconsistent it wasn't even funny. I have about 20 of them...they work great for a couple days, and then they are close to useless...after cleaning, they vape a little better, but not good enough. So i gave up on those.
I moved on to the Vivi Nova minis recently...and I did not have high hopes, but honestly I have been beyond pleasantly surprised. Even after cleaning some of the heads, they work like new when I put them back on. I've found the best vape for me to be with the 2.4ohm heads on my Twist at around 4.4v. I haven't tried the full size Vivi Nova V 2.5 yet...I personally like the size of the mini and don't feel like I need to go much bigger. Hopefully when you get those you don't have any issues. I finally feel like I can put aside all of my other gadgets, and am completely satisfied with my Twist and vivi nova minis. When my Twist is charging, I just use them on my regular eGo. I plan to get a second Twist so I always have one charged and ready to go.