I use a protank when I am at home, never had much problem with it. I do recoil mine though with thicker wick/evod bottom. I had a Vivi Nova for along time, it was ok.. it did seem to burn through liquid though and get dry hits, my girlfriend has it now and it does leak a fair amount, it is quite old at this point though. When I go on trips though I tend to take my agr carto
tank (easy to use/carry/no leaking). They are all kinda different in their own right as far as taste/vapor. One thing I can note is that if I toss my nova in my purse for a day it floods or leaks usually while I don't have the problem with carto
tank, and only once with my protank having a bit of liquid come out the top from being upside down for long time. As for that metal taste I believe it's from the top mouth piece I noticed it the first week I had the protank. .02