I have not yet tried the T3, (I am in a coop of some, but have not gotten them yet.) However I do like the Vivi a lot but I love the CE3 bottom
coils except that I get leaking in the CE3s. This is why I am going to try the T3s.
I agree with several people that have already posted and think you should
buy one of each and see which one you like better. I will suggest when you buy the vivi, go with the mini. It is almost the exact diameter as the twist.
Every time I ask for opinions on "one or another" of anything, I get about half of the people swearing by one and the other half swear by the other. I almost always end up trying both out and see for myself. For instance, I know several people that really liked the stormizers and I bought 2 of them and I couldn't get either one to work for me. Dry hits every single time! What works wonderfully for one person, doesn't do it for another.
Good luck with your journey and I hope you find what works for you!